1
|
Alkan C, Jurado-Cobena E, Ikegami T. Distinct Pathological Changes in Preweaning Mice Infected with Live-Attenuated Rift Valley Fever Virus Strains. Viruses 2024; 16:999. [PMID: 39066162 PMCID: PMC11281583 DOI: 10.3390/v16070999] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2024] [Revised: 06/18/2024] [Accepted: 06/20/2024] [Indexed: 07/28/2024] Open
Abstract
Rift Valley fever (RVF) is a mosquito-borne zoonotic viral disease endemic to Africa and the Middle East. Live-attenuated RVF vaccines have been studied for both veterinary and human use due to their strong immunogenicity and cost-effective manufacturing. The live-attenuated MP-12 vaccine has been conditionally approved for veterinary use in the U.S.A., and next-generation live-attenuated RVF vaccine candidates are being actively researched. Assessing the virulence phenotype of vaccine seeds or lots is crucial for managing vaccine safety. Previously, preweaning 19-day-old outbred CD1 mice have been used to evaluate the MP-12 strain. This study aimed to characterize the relative virulence of three live-attenuated RVF vaccine strains in 19-day-old inbred C57BL/6 mice: the recombinant MP-12 (rMP-12), the RVax-1, and the ∆NSs-∆NSm-rZH501 strains. Although this mouse model did not show dose-dependent pathogenesis, mice that succumbed to the infection exhibited distinct brain pathology. Mice infected with ∆NSs-∆NSm-rZH501 showed an infiltration of inflammatory cells associated with infected neurons, and focal lesions formed around virus-infected cells. In contrast, mice infected with rMP-12 or RVax-1 showed a minimal association of inflammatory cells in the brain, yet the virus spread diffusely. The preweaning model is likely useful for evaluating host responses to attenuated RVFV strains, although further refinement may be necessary to quantitate the virulence among different RVFV strains or vaccine lots.
Collapse
Affiliation(s)
- Cigdem Alkan
- Department of Pathology, The University of Texas Medical Branch at Galveston, Galveston, TX 77555, USA;
| | - Eduardo Jurado-Cobena
- Department of Microbiology and Immunology, The University of Texas Medical Branch at Galveston, Galveston, TX 77555, USA;
| | - Tetsuro Ikegami
- Department of Pathology, The University of Texas Medical Branch at Galveston, Galveston, TX 77555, USA;
- Center for Biodefense and Emerging Infectious Diseases, The University of Texas Medical Branch at Galveston, Galveston, TX 77555, USA
- Sealy Institute for Vaccine Sciences, The University of Texas Medical Branch at Galveston, Galveston, TX 77555, USA
| |
Collapse
|
2
|
Li M. Innate immune response against vector-borne bunyavirus infection and viral countermeasures. Front Cell Infect Microbiol 2024; 14:1365221. [PMID: 38711929 PMCID: PMC11070517 DOI: 10.3389/fcimb.2024.1365221] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2024] [Accepted: 03/29/2024] [Indexed: 05/08/2024] Open
Abstract
Bunyaviruses are a large group of important viral pathogens that cause significant diseases in humans and animals worldwide. Bunyaviruses are enveloped, single-stranded, negative-sense RNA viruses that infect a wide range of hosts. Upon entry into host cells, the components of viruses are recognized by host innate immune system, leading to the activation of downstream signaling cascades to induce interferons (IFNs) and other proinflammatory cytokines. IFNs bind to their receptors and upregulate the expression of hundreds of interferon-stimulated genes (ISGs). Many ISGs have antiviral activities and confer an antiviral state to host cells. For efficient replication and spread, viruses have evolved different strategies to antagonize IFN-mediated restriction. Here, we discuss recent advances in our understanding of the interactions between bunyaviruses and host innate immune response.
Collapse
Affiliation(s)
- Minghua Li
- Department of Pathology, University of Texas Medical Branch, Galveston, TX, United States
- Center for Biodefense and Emerging Infectious Diseases, University of Texas Medical Branch, Galveston, TX, United States
- Center for Tropical Diseases, University of Texas Medical Branch, Galveston, TX, United States
- Institute for Human Infections and Immunity, University of Texas Medical Branch, Galveston, TX, United States
| |
Collapse
|
3
|
Petraccione K, Ali MGH, Cyr N, Wahba HM, Stocker T, Akhrymuk M, Akhrymuk I, Panny L, Bracci N, Cafaro R, Sastre D, Silberfarb A, O’Maille P, Omichinski J, Kehn-Hall K. An LIR motif in the Rift Valley fever virus NSs protein is critical for the interaction with LC3 family members and inhibition of autophagy. PLoS Pathog 2024; 20:e1012093. [PMID: 38512999 PMCID: PMC10986958 DOI: 10.1371/journal.ppat.1012093] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2023] [Revised: 04/02/2024] [Accepted: 03/04/2024] [Indexed: 03/23/2024] Open
Abstract
Rift Valley fever virus (RVFV) is a viral zoonosis that causes severe disease in ruminants and humans. The nonstructural small (NSs) protein is the primary virulence factor of RVFV that suppresses the host's antiviral innate immune response. Bioinformatic analysis and AlphaFold structural modeling identified four putative LC3-interacting regions (LIR) motifs (NSs 1-4) in the RVFV NSs protein, which suggest that NSs interacts with the host LC3-family proteins. Using, isothermal titration calorimetry, X-ray crystallography, co-immunoprecipitation, and co-localization experiments, the C-terminal LIR motif (NSs4) was confirmed to interact with all six human LC3 proteins. Phenylalanine at position 261 (F261) within NSs4 was found to be critical for the interaction of NSs with LC3, retention of LC3 in the nucleus, as well as the inhibition of autophagy in RVFV infected cells. These results provide mechanistic insights into the ability of RVFV to overcome antiviral autophagy through the interaction of NSs with LC3 proteins.
Collapse
Affiliation(s)
- Kaylee Petraccione
- Department of Biomedical Sciences and Pathobiology, Virginia-Maryland College of Veterinary Medicine, Virginia Polytechnic Institute and State University, Blacksburg, Virginia, United States of America
- Center for Emerging, Zoonotic, and Arthropod-borne Pathogens, Virginia Polytechnic Institute and State University, Blacksburg, Virginia, United States of America
| | - Mohamed G. H. Ali
- Department of Biochemistry and Molecular Medicine, Université de Montréal, Montréal, Quebec, Canada
- Department of Biochemistry, Faculty of Pharmacy, Beni-Suef University, Beni-Suef, Egypt
| | - Normand Cyr
- Department of Biochemistry and Molecular Medicine, Université de Montréal, Montréal, Quebec, Canada
| | - Haytham M. Wahba
- Department of Biochemistry and Molecular Medicine, Université de Montréal, Montréal, Quebec, Canada
- Department of Biochemistry, Faculty of Pharmacy, Beni-Suef University, Beni-Suef, Egypt
| | - Timothy Stocker
- Department of Biomedical Sciences and Pathobiology, Virginia-Maryland College of Veterinary Medicine, Virginia Polytechnic Institute and State University, Blacksburg, Virginia, United States of America
| | - Maryna Akhrymuk
- Department of Biomedical Sciences and Pathobiology, Virginia-Maryland College of Veterinary Medicine, Virginia Polytechnic Institute and State University, Blacksburg, Virginia, United States of America
- Center for Emerging, Zoonotic, and Arthropod-borne Pathogens, Virginia Polytechnic Institute and State University, Blacksburg, Virginia, United States of America
| | - Ivan Akhrymuk
- Department of Biomedical Sciences and Pathobiology, Virginia-Maryland College of Veterinary Medicine, Virginia Polytechnic Institute and State University, Blacksburg, Virginia, United States of America
- Center for Emerging, Zoonotic, and Arthropod-borne Pathogens, Virginia Polytechnic Institute and State University, Blacksburg, Virginia, United States of America
| | - Lauren Panny
- Department of Biomedical Sciences and Pathobiology, Virginia-Maryland College of Veterinary Medicine, Virginia Polytechnic Institute and State University, Blacksburg, Virginia, United States of America
- Center for Emerging, Zoonotic, and Arthropod-borne Pathogens, Virginia Polytechnic Institute and State University, Blacksburg, Virginia, United States of America
| | - Nicole Bracci
- Department of Biomedical Sciences and Pathobiology, Virginia-Maryland College of Veterinary Medicine, Virginia Polytechnic Institute and State University, Blacksburg, Virginia, United States of America
- Center for Emerging, Zoonotic, and Arthropod-borne Pathogens, Virginia Polytechnic Institute and State University, Blacksburg, Virginia, United States of America
| | - Raphaël Cafaro
- Department of Biochemistry and Molecular Medicine, Université de Montréal, Montréal, Quebec, Canada
- Department of Biochemistry, Faculty of Pharmacy, Beni-Suef University, Beni-Suef, Egypt
| | - Danuta Sastre
- Biosciences Division, SRI International, Menlo Park, California, United States of America
| | - Andrew Silberfarb
- Artificial Intelligence Center, SRI International, Menlo Park, California, United States of America
| | - Paul O’Maille
- Biosciences Division, SRI International, Menlo Park, California, United States of America
| | - James Omichinski
- Department of Biochemistry and Molecular Medicine, Université de Montréal, Montréal, Quebec, Canada
| | - Kylene Kehn-Hall
- Department of Biomedical Sciences and Pathobiology, Virginia-Maryland College of Veterinary Medicine, Virginia Polytechnic Institute and State University, Blacksburg, Virginia, United States of America
- Center for Emerging, Zoonotic, and Arthropod-borne Pathogens, Virginia Polytechnic Institute and State University, Blacksburg, Virginia, United States of America
| |
Collapse
|
4
|
Xu J, Guo R, Wen N, Li L, Yi Y, Chen J, He Z, Yang J, Xiao ZXJ, Niu M. FBXO3 stabilizes USP4 and Twist1 to promote PI3K-mediated breast cancer metastasis. PLoS Biol 2023; 21:e3002446. [PMID: 38134227 PMCID: PMC10745200 DOI: 10.1371/journal.pbio.3002446] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2023] [Accepted: 11/24/2023] [Indexed: 12/24/2023] Open
Abstract
Tumor metastasis is the major cause of breast cancer morbidity and mortality. It has been reported that the F-box protein FBXO3 functions as an E3 ubiquitin ligase in regulating various biological processes, including host autoimmune, antiviral innate immunity, and inflammatory response. However, the role of FBXO3 in tumor metastasis remains elusive. We have previously shown that ΔNp63α is a common inhibitory target in oncogene-induced cell motility and tumor metastasis. In this study, we show that FBXO3 plays a vital role in PI3K-mediated breast cancer metastasis independent of its E3 ligase activity and ΔNp63α in breast cancer cells and in mouse. FBXO3 can bind to and stabilize USP4, leading to Twist1 protein stabilization and increased breast cancer cell migration and tumor metastasis. Mechanistically, FBXO3 disrupts the interaction between USP4 and aspartyl aminopeptidase (DNPEP), thereby protecting USP4 from DNPEP-mediated degradation. Furthermore, p110αH1047R facilitates the phosphorylation and stabilization of FBXO3 in an ERK1-dependent manner. Knockdown of either FBXO3 or USP4 leads to significant inhibition of PI3K-induced breast cancer metastasis. Clinically, elevated expression of p110α/FBXO3/USP4/Twist1 is associated with poor overall survival (OS) and recurrence-free survival (RFS) of breast cancer patients. Taken together, this study reveals that the FBXO3-USP4-Twist1 axis is pivotal in PI3K-mediated breast tumor metastasis and that FBXO3/USP4 may be potential therapeutic targets for breast cancer treatment.
Collapse
Affiliation(s)
- Jing Xu
- Center of Growth, Metabolism and Aging, Key Laboratory of Bio-Resource and Eco-Environment, Ministry of Education, College of Life Sciences, Sichuan University, Chengdu, China
| | - Rongtian Guo
- Center of Growth, Metabolism and Aging, Key Laboratory of Bio-Resource and Eco-Environment, Ministry of Education, College of Life Sciences, Sichuan University, Chengdu, China
| | - Nasi Wen
- Center of Growth, Metabolism and Aging, Key Laboratory of Bio-Resource and Eco-Environment, Ministry of Education, College of Life Sciences, Sichuan University, Chengdu, China
| | - Luping Li
- Center of Growth, Metabolism and Aging, Key Laboratory of Bio-Resource and Eco-Environment, Ministry of Education, College of Life Sciences, Sichuan University, Chengdu, China
| | - Yong Yi
- Center of Growth, Metabolism and Aging, Key Laboratory of Bio-Resource and Eco-Environment, Ministry of Education, College of Life Sciences, Sichuan University, Chengdu, China
| | - Jingzhen Chen
- Center of Growth, Metabolism and Aging, Key Laboratory of Bio-Resource and Eco-Environment, Ministry of Education, College of Life Sciences, Sichuan University, Chengdu, China
| | - Zongyu He
- Center of Growth, Metabolism and Aging, Key Laboratory of Bio-Resource and Eco-Environment, Ministry of Education, College of Life Sciences, Sichuan University, Chengdu, China
| | - Jian Yang
- Center of Growth, Metabolism and Aging, Key Laboratory of Bio-Resource and Eco-Environment, Ministry of Education, College of Life Sciences, Sichuan University, Chengdu, China
| | - Zhi-Xiong Jim Xiao
- Center of Growth, Metabolism and Aging, Key Laboratory of Bio-Resource and Eco-Environment, Ministry of Education, College of Life Sciences, Sichuan University, Chengdu, China
| | - Mengmeng Niu
- Center of Growth, Metabolism and Aging, Key Laboratory of Bio-Resource and Eco-Environment, Ministry of Education, College of Life Sciences, Sichuan University, Chengdu, China
| |
Collapse
|
5
|
Schoen A, Hölzer M, Müller MA, Wallerang KB, Drosten C, Marz M, Lamp B, Weber F. Functional comparisons of the virus sensor RIG-I from humans, the microbat Myotis daubentonii, and the megabat Rousettus aegyptiacus, and their response to SARS-CoV-2 infection. J Virol 2023; 97:e0020523. [PMID: 37728614 PMCID: PMC10653997 DOI: 10.1128/jvi.00205-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2023] [Accepted: 07/09/2023] [Indexed: 09/21/2023] Open
Abstract
IMPORTANCE A common hypothesis holds that bats (order Chiroptera) are outstanding reservoirs for zoonotic viruses because of a special antiviral interferon (IFN) system. However, functional studies about key components of the bat IFN system are rare. RIG-I is a cellular sensor for viral RNA signatures that activates the antiviral signaling chain to induce IFN. We cloned and functionally characterized RIG-I genes from two species of the suborders Yangochiroptera and Yinpterochiroptera. The bat RIG-Is were conserved in their sequence and domain organization, and similar to human RIG-I in (i) mediating virus- and IFN-activated gene expression, (ii) antiviral signaling, (iii) temperature dependence, and (iv) recognition of RNA ligands. Moreover, RIG-I of Rousettus aegyptiacus (suborder Yinpterochiroptera) and of humans were found to recognize SARS-CoV-2 infection. Thus, members of both bat suborders encode RIG-Is that are comparable to their human counterpart. The ability of bats to harbor zoonotic viruses therefore seems due to other features.
Collapse
Affiliation(s)
- Andreas Schoen
- Institute for Virology, FB10-Veterinary Medicine, Justus-Liebig University, Giessen, Germany
| | - Martin Hölzer
- RNA Bioinformatics and High-Throughput Analysis, Friedrich Schiller University Jena, Jena, Germany
- European Virus Bioinformatics Center, Jena, Germany
| | - Marcel A. Müller
- German Centre for Infection Research (DZIF), Partner Sites Giessen and Charité, Berlin, Germany
- Institute of Virology, Charité-Universitätsmedizin Berlin, corporate member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Berlin, Germany
| | - Kai B. Wallerang
- Institute for Virology, FB10-Veterinary Medicine, Justus-Liebig University, Giessen, Germany
| | - Christian Drosten
- European Virus Bioinformatics Center, Jena, Germany
- German Centre for Infection Research (DZIF), Partner Sites Giessen and Charité, Berlin, Germany
- Institute of Virology, Charité-Universitätsmedizin Berlin, corporate member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Berlin, Germany
| | - Manja Marz
- RNA Bioinformatics and High-Throughput Analysis, Friedrich Schiller University Jena, Jena, Germany
- European Virus Bioinformatics Center, Jena, Germany
| | - Benjamin Lamp
- Institute for Virology, FB10-Veterinary Medicine, Justus-Liebig University, Giessen, Germany
| | - Friedemann Weber
- Institute for Virology, FB10-Veterinary Medicine, Justus-Liebig University, Giessen, Germany
- European Virus Bioinformatics Center, Jena, Germany
- German Centre for Infection Research (DZIF), Partner Sites Giessen and Charité, Berlin, Germany
| |
Collapse
|
6
|
Emslander Q, Krey K, Hamad S, Maidl S, Oubraham L, Hesse J, Henrici A, Austen K, Mergner J, Grass V, Pichlmair A. MDM2 Influences ACE2 Stability and SARS-CoV-2 Uptake. Viruses 2023; 15:1763. [PMID: 37632105 PMCID: PMC10459000 DOI: 10.3390/v15081763] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2023] [Revised: 07/20/2023] [Accepted: 08/07/2023] [Indexed: 08/27/2023] Open
Abstract
Angiotensin-converting enzyme 2 (ACE2) is the central entry receptor for SARS-CoV-2. However, surprisingly little is known about the effects of host regulators on ACE2 localization, expression, and the associated influence on SARS-CoV-2 infection. Here we identify that ACE2 expression levels are regulated by the E3 ligase MDM2 and that MDM2 levels indirectly influence infection with SARS-CoV-2. Genetic depletion of MDM2 elevated ACE2 expression levels, which strongly promoted infection with all SARS-CoV-2 isolates tested. SARS-CoV-2 spike-pseudotyped viruses and the uptake of non-replication-competent virus-like particles showed that MDM2 affects the viral uptake process. MDM2 ubiquitinates Lysine 788 of ACE2 to induce proteasomal degradation, and degradation of this residue led to higher ACE2 expression levels and superior virus particle uptake. Our study illustrates that cellular regulators of ACE2 stability, such as MDM2, play an important role in defining the infection capabilities of SARS-CoV-2.
Collapse
Affiliation(s)
- Quirin Emslander
- Institute of Virology, School of Medicine, Technical University of Munich (TUM), 81675 Munich, Germany (S.H.)
| | - Karsten Krey
- Institute of Virology, School of Medicine, Technical University of Munich (TUM), 81675 Munich, Germany (S.H.)
| | - Sabri Hamad
- Institute of Virology, School of Medicine, Technical University of Munich (TUM), 81675 Munich, Germany (S.H.)
| | - Susanne Maidl
- Institute of Virology, School of Medicine, Technical University of Munich (TUM), 81675 Munich, Germany (S.H.)
| | - Lila Oubraham
- Institute of Virology, School of Medicine, Technical University of Munich (TUM), 81675 Munich, Germany (S.H.)
| | - Joshua Hesse
- Institute of Virology, School of Medicine, Technical University of Munich (TUM), 81675 Munich, Germany (S.H.)
| | - Alexander Henrici
- Institute of Virology, School of Medicine, Technical University of Munich (TUM), 81675 Munich, Germany (S.H.)
| | - Katharina Austen
- Institute of Virology, School of Medicine, Technical University of Munich (TUM), 81675 Munich, Germany (S.H.)
| | - Julia Mergner
- BayBioMS@MRI—Bavarian Center for Biomolecular Mass Spectrometry at Klinikum Rechts der Isar, Technical University of Munich, 81675 Munich, Germany
| | - Vincent Grass
- Institute of Virology, School of Medicine, Technical University of Munich (TUM), 81675 Munich, Germany (S.H.)
| | - Andreas Pichlmair
- Institute of Virology, School of Medicine, Technical University of Munich (TUM), 81675 Munich, Germany (S.H.)
- German Centre for Infection Research (DZIF), Partner site Munich, 81675 Munich, Germany
- Center of Immunology of Viral Infection (CiViA), Aarhus University, 8000 Aarhus, Denmark
| |
Collapse
|
7
|
Godbold GD, Hewitt FC, Kappell AD, Scholz MB, Agar SL, Treangen TJ, Ternus KL, Sandbrink JB, Koblentz GD. Improved understanding of biorisk for research involving microbial modification using annotated sequences of concern. Front Bioeng Biotechnol 2023; 11:1124100. [PMID: 37180048 PMCID: PMC10167326 DOI: 10.3389/fbioe.2023.1124100] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2022] [Accepted: 04/11/2023] [Indexed: 05/15/2023] Open
Abstract
Regulation of research on microbes that cause disease in humans has historically been focused on taxonomic lists of 'bad bugs'. However, given our increased knowledge of these pathogens through inexpensive genome sequencing, 5 decades of research in microbial pathogenesis, and the burgeoning capacity of synthetic biologists, the limitations of this approach are apparent. With heightened scientific and public attention focused on biosafety and biosecurity, and an ongoing review by US authorities of dual-use research oversight, this article proposes the incorporation of sequences of concern (SoCs) into the biorisk management regime governing genetic engineering of pathogens. SoCs enable pathogenesis in all microbes infecting hosts that are 'of concern' to human civilization. Here we review the functions of SoCs (FunSoCs) and discuss how they might bring clarity to potentially problematic research outcomes involving infectious agents. We believe that annotation of SoCs with FunSoCs has the potential to improve the likelihood that dual use research of concern is recognized by both scientists and regulators before it occurs.
Collapse
Affiliation(s)
| | | | | | | | - Stacy L. Agar
- Signature Science, LLC, Charlottesville, VA, United States
| | - Todd J. Treangen
- Department of Computer Science, Rice University, Houston, TX, United States
| | | | - Jonas B. Sandbrink
- Nuffield Department of Medicine, University of Oxford, Oxford, United Kingdom
| | - Gregory D. Koblentz
- Schar School of Policy and Government, George Mason University, Arlington, VA, United States
| |
Collapse
|
8
|
Bhattacharjee S, Ghosh D, Saha R, Sarkar R, Kumar S, Khokhar M, Pandey RK. Mechanism of Immune Evasion in Mosquito-Borne Diseases. Pathogens 2023; 12:pathogens12050635. [PMID: 37242305 DOI: 10.3390/pathogens12050635] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2023] [Revised: 04/20/2023] [Accepted: 04/21/2023] [Indexed: 05/28/2023] Open
Abstract
In recent decades, mosquito-borne illnesses have emerged as a major health burden in many tropical regions. These diseases, such as malaria, dengue fever, chikungunya, yellow fever, Zika virus infection, Rift Valley fever, Japanese encephalitis, and West Nile virus infection, are transmitted through the bite of infected mosquitoes. These pathogens have been shown to interfere with the host's immune system through adaptive and innate immune mechanisms, as well as the human circulatory system. Crucial immune checkpoints such as antigen presentation, T cell activation, differentiation, and proinflammatory response play a vital role in the host cell's response to pathogenic infection. Furthermore, these immune evasions have the potential to stimulate the human immune system, resulting in other associated non-communicable diseases. This review aims to advance our understanding of mosquito-borne diseases and the immune evasion mechanisms by associated pathogens. Moreover, it highlights the adverse outcomes of mosquito-borne disease.
Collapse
Affiliation(s)
| | - Debanjan Ghosh
- Department of Biotechnology, Pondicherry University, Puducherry 605014, India
| | - Rounak Saha
- Department of Biochemistry and Molecular Biology, Pondicherry University, Puducherry 605014, India
| | - Rima Sarkar
- DBT Rajiv Gandhi Centre for Biotechnology, Thiruvananthapuram 695014, India
| | - Saurav Kumar
- DBT Rajiv Gandhi Centre for Biotechnology, Thiruvananthapuram 695014, India
| | - Manoj Khokhar
- Department of Biochemistry, AIIMS, Jodhpur 342005, India
| | - Rajan Kumar Pandey
- Department of Medical Biochemistry and Biophysics, Karolinska Institute, 171 77 Solna, Sweden
| |
Collapse
|
9
|
Tercero B, Terasaki K, Narayanan K, Makino S. Mechanistic insight into the efficient packaging of antigenomic S RNA into Rift Valley fever virus particles. Front Cell Infect Microbiol 2023; 13:1132757. [PMID: 36875526 PMCID: PMC9978001 DOI: 10.3389/fcimb.2023.1132757] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2022] [Accepted: 02/06/2023] [Indexed: 02/18/2023] Open
Abstract
Rift Valley fever virus (RVFV), a bunyavirus, has a single-stranded, negative-sense tri-segmented RNA genome, consisting of L, M and S RNAs. An infectious virion carries two envelope glycoproteins, Gn and Gc, along with ribonucleoprotein complexes composed of encapsidated viral RNA segments. The antigenomic S RNA, which serves as the template of the mRNA encoding a nonstructural protein, NSs, an interferon antagonist, is also efficiently packaged into RVFV particles. An interaction between Gn and viral ribonucleoprotein complexes, including the direct binding of Gn to viral RNAs, drives viral RNA packaging into RVFV particles. To understand the mechanism of efficient antigenomic S RNA packaging in RVFV, we identified the regions in viral RNAs that directly interact with Gn by performing UV-crosslinking and immunoprecipitation of RVFV-infected cell lysates with anti-Gn antibody followed by high-throughput sequencing analysis (CLIP-seq analysis). Our data suggested the presence of multiple Gn-binding sites in RVFV RNAs, including a prominent Gn-binding site within the 3' noncoding region of the antigenomic S RNA. We found that the efficient packaging of antigenomic S RNA was abrogated in a RVFV mutant lacking a part of this prominent Gn-binding site within the 3' noncoding region. Also, the mutant RVFV, but not the parental RVFV, triggered the early induction of interferon-β mRNA expression after infection. These data suggest that the direct binding of Gn to the RNA element within the 3' noncoding region of the antigenomic S RNA promoted the efficient packaging of antigenomic S RNA into virions. Furthermore, the efficient packaging of antigenomic S RNA into RVFV particles, driven by the RNA element, facilitated the synthesis of viral mRNA encoding NSs immediately after infection, resulting in the suppression of interferon-β mRNA expression.
Collapse
Affiliation(s)
- Breanna Tercero
- Department of Microbiology and Immunology, The University of Texas Medical Branch, Galveston, TX, United States
| | - Kaori Terasaki
- Department of Microbiology and Immunology, The University of Texas Medical Branch, Galveston, TX, United States
- Institute for Human Infections and Immunity, The University of Texas Medical Branch, Galveston, TX, United States
| | - Krishna Narayanan
- Department of Microbiology and Immunology, The University of Texas Medical Branch, Galveston, TX, United States
| | - Shinji Makino
- Department of Microbiology and Immunology, The University of Texas Medical Branch, Galveston, TX, United States
- Institute for Human Infections and Immunity, The University of Texas Medical Branch, Galveston, TX, United States
- Center for Biodefense and Emerging Infectious Diseases, The University of Texas Medical Branch, Galveston, TX, United States
- UTMB Center for Tropical Diseases, The University of Texas Medical Branch, Galveston, TX, United States
- The Sealy Institute for Vaccine Sciences, The University of Texas Medical Branch, Galveston, TX, United States
| |
Collapse
|
10
|
Wang X, Yuan Y, Liu Y, Zhang L. Arm race between Rift Valley fever virus and host. Front Immunol 2022; 13:1084230. [PMID: 36618346 PMCID: PMC9813963 DOI: 10.3389/fimmu.2022.1084230] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2022] [Accepted: 12/12/2022] [Indexed: 12/24/2022] Open
Abstract
Rift Valley fever (RVF) is a zoonotic disease caused by Rift Valley fever virus (RVFV), an emerging arbovirus within the Phenuiviridae family of Bunyavirales that has potential to cause severe diseases in both humans and livestock. It increases the incidence of abortion or foetal malformation in ruminants and leads to clinical manifestations like encephalitis or haemorrhagic fever in humans. Upon virus invasion, the innate immune system from the cell or the organism is activated to produce interferon (IFN) and prevent virus proliferation. Meanwhile, RVFV initiates countermeasures to limit antiviral responses at transcriptional and protein levels. RVFV nonstructural proteins (NSs) are the key virulent factors that not only perform immune evasion but also impact the cell replication cycle and has cytopathic effects. In this review, we summarize the innate immunity host cells employ depending on IFN signal transduction pathways, as well as the immune evasion mechanisms developed by RVFV primarily with the inhibitory activity of NSs protein. Clarifying the arms race between host innate immunity and RVFV immune evasion provides new avenues for drug target screening and offers possible solutions to current and future epidemics.
Collapse
Affiliation(s)
- Xiao Wang
- Department of Infectious Diseases, Shandong Provincial Hospital Affiliated to Shandong First Medical University, Jinan, Shandong, China,Department of Pathogen Biology, School of Clinical and Basic Medical Sciences, Shandong First Medical University and Shandong Academy of Medical Sciences, Jinan, Shandong, China,Medical Science and Technology Innovation Center, Shandong First Medical University and Shandong Academy of Medical Sciences, Jinan, Shandong, China
| | - Yupei Yuan
- Department of Pathogen Biology, School of Clinical and Basic Medical Sciences, Shandong First Medical University and Shandong Academy of Medical Sciences, Jinan, Shandong, China
| | - Yihan Liu
- Department of Pathogen Biology, School of Clinical and Basic Medical Sciences, Shandong First Medical University and Shandong Academy of Medical Sciences, Jinan, Shandong, China,Medical Science and Technology Innovation Center, Shandong First Medical University and Shandong Academy of Medical Sciences, Jinan, Shandong, China
| | - Leiliang Zhang
- Department of Infectious Diseases, Shandong Provincial Hospital Affiliated to Shandong First Medical University, Jinan, Shandong, China,Department of Pathogen Biology, School of Clinical and Basic Medical Sciences, Shandong First Medical University and Shandong Academy of Medical Sciences, Jinan, Shandong, China,Medical Science and Technology Innovation Center, Shandong First Medical University and Shandong Academy of Medical Sciences, Jinan, Shandong, China,*Correspondence: Leiliang Zhang,
| |
Collapse
|
11
|
Das A, Wang X, Wei J, Hoji A, Coon TA, Popescu I, Brown M, Frizzell S, Iasella CJ, Noda K, Sembrat J, Devonshire K, Hannan SJ, Snyder ME, Pilewski J, Sanchez PG, Chandra D, Mallampalli RK, Alder JK, Chen BB, McDyer JF. Cross-Regulation of F-Box Protein FBXL2 with T-bet and TNF-α during Acute and Chronic Lung Allograft Rejection. JOURNAL OF IMMUNOLOGY (BALTIMORE, MD. : 1950) 2022; 209:1788-1795. [PMID: 36113884 PMCID: PMC9588753 DOI: 10.4049/jimmunol.2200245] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/05/2022] [Accepted: 08/15/2022] [Indexed: 01/04/2023]
Abstract
Chronic lung allograft dysfunction is the major barrier to long-term survival in lung transplant recipients. Evidence supports type 1 alloimmunity as the predominant response in acute/chronic lung rejection, but the immunoregulatory mechanisms remain incompletely understood. We studied the combinatorial F-box E3 ligase system: F-box protein 3 (FBXO3; proinflammatory) and F-box and leucine-rich repeat protein 2 (FBXL2; anti-inflammatory and regulates TNFR-associated factor [TRAF] protein). Using the mouse orthotopic lung transplant model, we evaluated allografts from BALB/c → C57BL/6 (acute rejection; day 10) and found significant induction of FBXO3 and diminished FBXL2 protein along with elevated T-bet, IFN-γ, and TRAF proteins 1-5 compared with isografts. In the acute model, treatment with costimulation blockade (MR1/CTLA4-Ig) resulted in attenuated FBXO3, preserved FBXL2, and substantially reduced T-bet, IFN-γ, and TRAFs 1-5, consistent with a key role for type 1 alloimmunity. Immunohistochemistry revealed significant changes in the FBXO3/FBXL2 balance in airway epithelia and infiltrating mononuclear cells during rejection compared with isografts or costimulation blockade-treated allografts. In the chronic lung rejection model, DBA/2J/C57BL/6F1 > DBA/2J (day 28), we observed persistently elevated FBXO3/FBXL2 balance and T-bet/IFN-γ protein and similar findings from lung transplant recipient lungs with chronic lung allograft dysfunction versus controls. We hypothesized that FBXL2 regulated T-bet and found FBXL2 was sufficient to polyubiquitinate T-bet and coimmunoprecipitated with T-bet on pulldown experiments and vice versa in Jurkat cells. Transfection with FBXL2 diminished T-bet protein in a dose-dependent manner in mouse lung epithelial cells. In testing type 1 cytokines, TNF-α was found to negatively regulate FBXL2 protein and mRNA levels. Together, our findings show the combinatorial E3 ligase FBXO3/FBXL2 system plays a role in the regulation of T-bet through FBXL2, with negative cross-regulation of TNF-α on FBXL2 during lung allograft rejection.
Collapse
Affiliation(s)
- Antu Das
- Division of Pulmonary, Allergy, and Critical Care Medicine, Department of Medicine, University of Pittsburgh School of Medicine; Pittsburgh, Pennsylvania, 15213, USA
| | - Xingan Wang
- Division of Pulmonary, Allergy, and Critical Care Medicine, Department of Medicine, University of Pittsburgh School of Medicine; Pittsburgh, Pennsylvania, 15213, USA
| | - Jianxin Wei
- Division of Pulmonary, Allergy, and Critical Care Medicine, Department of Medicine, University of Pittsburgh School of Medicine; Pittsburgh, Pennsylvania, 15213, USA
| | - Aki Hoji
- Division of Pulmonary, Allergy, and Critical Care Medicine, Department of Medicine, University of Pittsburgh School of Medicine; Pittsburgh, Pennsylvania, 15213, USA
| | - Tiffany A. Coon
- Division of Pulmonary, Allergy, and Critical Care Medicine, Department of Medicine, University of Pittsburgh School of Medicine; Pittsburgh, Pennsylvania, 15213, USA
| | - Iulia Popescu
- Division of Pulmonary, Allergy, and Critical Care Medicine, Department of Medicine, University of Pittsburgh School of Medicine; Pittsburgh, Pennsylvania, 15213, USA
| | - Mark Brown
- Division of Pulmonary, Allergy, and Critical Care Medicine, Department of Medicine, University of Pittsburgh School of Medicine; Pittsburgh, Pennsylvania, 15213, USA
| | - Sheila Frizzell
- Division of Pulmonary, Allergy, and Critical Care Medicine, Department of Medicine, University of Pittsburgh School of Medicine; Pittsburgh, Pennsylvania, 15213, USA
| | - Carlo J. Iasella
- Department of Pharmacy and Therapeutics, University of Pittsburgh School of Pharmacy; Pittsburgh, Pennsylvania, 15213, USA
| | - Kentaro Noda
- Department of Cardiothoracic Surgery, University of Pittsburgh School of Medicine; Pittsburgh, Pennsylvania, 15213, USA
| | - John Sembrat
- Division of Pulmonary, Allergy, and Critical Care Medicine, Department of Medicine, University of Pittsburgh School of Medicine; Pittsburgh, Pennsylvania, 15213, USA
| | - Kaitlyn Devonshire
- Division of Pulmonary, Allergy, and Critical Care Medicine, Department of Medicine, University of Pittsburgh School of Medicine; Pittsburgh, Pennsylvania, 15213, USA
| | - Stefanie J. Hannan
- Division of Pulmonary, Allergy, and Critical Care Medicine, Department of Medicine, University of Pittsburgh School of Medicine; Pittsburgh, Pennsylvania, 15213, USA
| | - Mark E. Snyder
- Division of Pulmonary, Allergy, and Critical Care Medicine, Department of Medicine, University of Pittsburgh School of Medicine; Pittsburgh, Pennsylvania, 15213, USA
| | - Joseph Pilewski
- Division of Pulmonary, Allergy, and Critical Care Medicine, Department of Medicine, University of Pittsburgh School of Medicine; Pittsburgh, Pennsylvania, 15213, USA
| | - Pablo G. Sanchez
- Department of Cardiothoracic Surgery, University of Pittsburgh School of Medicine; Pittsburgh, Pennsylvania, 15213, USA
| | - Divay Chandra
- Division of Pulmonary, Allergy, and Critical Care Medicine, Department of Medicine, University of Pittsburgh School of Medicine; Pittsburgh, Pennsylvania, 15213, USA
| | - Rama K. Mallampalli
- Department of Medicine, Ohio State University School of Medicine; Columbus, Ohio, 43210, USA
| | - Jonathan K. Alder
- Division of Pulmonary, Allergy, and Critical Care Medicine, Department of Medicine, University of Pittsburgh School of Medicine; Pittsburgh, Pennsylvania, 15213, USA
| | - Bill B. Chen
- Division of Pulmonary, Allergy, and Critical Care Medicine, Department of Medicine, University of Pittsburgh School of Medicine; Pittsburgh, Pennsylvania, 15213, USA,Aging Institute, Department of Medicine, University of Pittsburgh School of Medicine; Pittsburgh, Pennsylvania, 15213, USA
| | - John F. McDyer
- Division of Pulmonary, Allergy, and Critical Care Medicine, Department of Medicine, University of Pittsburgh School of Medicine; Pittsburgh, Pennsylvania, 15213, USA
| |
Collapse
|
12
|
Gulyas L, Glaunsinger BA. RNA polymerase II subunit modulation during viral infection and cellular stress. Curr Opin Virol 2022; 56:101259. [PMID: 36162260 PMCID: PMC10150648 DOI: 10.1016/j.coviro.2022.101259] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2022] [Revised: 08/10/2022] [Accepted: 08/15/2022] [Indexed: 11/03/2022]
Abstract
Control of gene expression, including transcription, is central in dictating the outcome of viral infection. One of the profound alterations induced by viruses is modification to the integrity and function of eukaryotic RNA polymerase II (Pol II). Here, we discuss how infection perturbs the Pol II complex by altering subunit phosphorylation and turnover, as well as how cellular genotoxic stress (e.g. DNA damage) elicits similar outcomes. By highlighting emerging parallels and differences in Pol II control during viral infection and abiotic stress, we hope to bolster identification of pathways that target Pol II and regulate the transcriptome.
Collapse
Affiliation(s)
- Leah Gulyas
- Department of Plant and Microbial Biology, University of California, Berkeley, CA 94720, USA
| | - Britt A Glaunsinger
- Department of Plant and Microbial Biology, University of California, Berkeley, CA 94720, USA; Department of Molecular and Cell Biology, University of California, Berkeley, CA 94720, USA; Howard Hughes Medical Institute, University of California, Berkeley, CA 94709, USA.
| |
Collapse
|
13
|
Boshra H. An Overview of the Infectious Cycle of Bunyaviruses. Viruses 2022; 14:v14102139. [PMID: 36298693 PMCID: PMC9610998 DOI: 10.3390/v14102139] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2022] [Revised: 09/19/2022] [Accepted: 09/26/2022] [Indexed: 11/17/2022] Open
Abstract
Bunyaviruses represent the largest group of RNA viruses and are the causative agent of a variety of febrile and hemorrhagic illnesses. Originally characterized as a single serotype in Africa, the number of described bunyaviruses now exceeds over 500, with its presence detected around the world. These predominantly tri-segmented, single-stranded RNA viruses are transmitted primarily through arthropod and rodent vectors and can infect a wide variety of animals and plants. Although encoding for a small number of proteins, these viruses can inflict potentially fatal disease outcomes and have even developed strategies to suppress the innate antiviral immune mechanisms of the infected host. This short review will attempt to provide an overall description of the order Bunyavirales, describing the mechanisms behind their infection, replication, and their evasion of the host immune response. Furthermore, the historical context of these viruses will be presented, starting from their original discovery almost 80 years ago to the most recent research pertaining to viral replication and host immune response.
Collapse
Affiliation(s)
- Hani Boshra
- Global Urgent and Advanced Research and Development (GUARD), 911 Rue Principale, Batiscan, QC G0X 1A0, Canada
| |
Collapse
|
14
|
Hufsky F, Beslic D, Boeckaerts D, Duchene S, González-Tortuero E, Gruber AJ, Guo J, Jansen D, Juma J, Kongkitimanon K, Luque A, Ritsch M, Lencioni Lovate G, Nishimura L, Pas C, Domingo E, Hodcroft E, Lemey P, Sullivan MB, Weber F, González-Candelas F, Krautwurst S, Pérez-Cataluña A, Randazzo W, Sánchez G, Marz M. The International Virus Bioinformatics Meeting 2022. Viruses 2022; 14:973. [PMID: 35632715 PMCID: PMC9144528 DOI: 10.3390/v14050973] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2022] [Accepted: 04/28/2022] [Indexed: 12/22/2022] Open
Abstract
The International Virus Bioinformatics Meeting 2022 took place online, on 23-25 March 2022, and has attracted about 380 participants from all over the world. The goal of the meeting was to provide a meaningful and interactive scientific environment to promote discussion and collaboration and to inspire and suggest new research directions and questions. The participants created a highly interactive scientific environment even without physical face-to-face interactions. This meeting is a focal point to gain an insight into the state-of-the-art of the virus bioinformatics research landscape and to interact with researchers in the forefront as well as aspiring young scientists. The meeting featured eight invited and 18 contributed talks in eight sessions on three days, as well as 52 posters, which were presented during three virtual poster sessions. The main topics were: SARS-CoV-2, viral emergence and surveillance, virus-host interactions, viral sequence analysis, virus identification and annotation, phages, and viral diversity. This report summarizes the main research findings and highlights presented at the meeting.
Collapse
Affiliation(s)
- Franziska Hufsky
- European Virus Bioinformatics Center, 07743 Jena, Germany; (E.G.-T.); (A.J.G.); (J.G.); (D.J.); (K.K.); (A.L.); (M.R.); (G.L.L.); (L.N.); (E.D.); (E.H.); (P.L.); (M.B.S.); (F.W.); (F.G.-C.); (A.P.-C.); (W.R.); (G.S.)
- RNA Bioinformatics and High-Throughput Analysis, Friedrich Schiller University Jena, 07743 Jena, Germany;
| | - Denis Beslic
- Methodology and Research Infrastructure, MF1 Bioinformatics, Robert Koch Institute, 13353 Berlin, Germany;
| | - Dimitri Boeckaerts
- Laboratory of Applied Biotechnology, Department of Biotechnology, Ghent University, 9000 Ghent, Belgium; (D.B.); (C.P.)
- KERMIT, Department of Data Analysis and Mathematical Modelling, Ghent University, 9000 Ghent, Belgium
| | - Sebastian Duchene
- Peter Doherty Institute for Infection and Immunity, University of Melbourne, Melbourne 3000, Australia;
| | - Enrique González-Tortuero
- European Virus Bioinformatics Center, 07743 Jena, Germany; (E.G.-T.); (A.J.G.); (J.G.); (D.J.); (K.K.); (A.L.); (M.R.); (G.L.L.); (L.N.); (E.D.); (E.H.); (P.L.); (M.B.S.); (F.W.); (F.G.-C.); (A.P.-C.); (W.R.); (G.S.)
- School of Science, Engineering and Environment (SEE), University of Salford, Salford M5 4WT, UK
| | - Andreas J. Gruber
- European Virus Bioinformatics Center, 07743 Jena, Germany; (E.G.-T.); (A.J.G.); (J.G.); (D.J.); (K.K.); (A.L.); (M.R.); (G.L.L.); (L.N.); (E.D.); (E.H.); (P.L.); (M.B.S.); (F.W.); (F.G.-C.); (A.P.-C.); (W.R.); (G.S.)
- Department of Biology, University of Konstanz, 78464 Konstanz, Germany
| | - Jiarong Guo
- European Virus Bioinformatics Center, 07743 Jena, Germany; (E.G.-T.); (A.J.G.); (J.G.); (D.J.); (K.K.); (A.L.); (M.R.); (G.L.L.); (L.N.); (E.D.); (E.H.); (P.L.); (M.B.S.); (F.W.); (F.G.-C.); (A.P.-C.); (W.R.); (G.S.)
- Departments of Microbiology, and Civil, Environmental, and Geodetic Engineering, Ohio State University, Columbus, OH 43210, USA
| | - Daan Jansen
- European Virus Bioinformatics Center, 07743 Jena, Germany; (E.G.-T.); (A.J.G.); (J.G.); (D.J.); (K.K.); (A.L.); (M.R.); (G.L.L.); (L.N.); (E.D.); (E.H.); (P.L.); (M.B.S.); (F.W.); (F.G.-C.); (A.P.-C.); (W.R.); (G.S.)
- Department of Microbiology, Immunology and Transplantation, Rega Institute, Laboratory of Viral Metagenomics, KU Leuven, 3000 Leuven, Belgium
| | - John Juma
- International Livestock Research Institute (ILRI), Nairobi 00100, Kenya;
- South African National Bioinformatics Institute, South African MRC Bioinformatics Unit, Cape Town 7530, South Africa
| | - Kunaphas Kongkitimanon
- European Virus Bioinformatics Center, 07743 Jena, Germany; (E.G.-T.); (A.J.G.); (J.G.); (D.J.); (K.K.); (A.L.); (M.R.); (G.L.L.); (L.N.); (E.D.); (E.H.); (P.L.); (M.B.S.); (F.W.); (F.G.-C.); (A.P.-C.); (W.R.); (G.S.)
- Methodology and Research Infrastructure, MF1 Bioinformatics, Robert Koch Institute, 13353 Berlin, Germany;
| | - Antoni Luque
- European Virus Bioinformatics Center, 07743 Jena, Germany; (E.G.-T.); (A.J.G.); (J.G.); (D.J.); (K.K.); (A.L.); (M.R.); (G.L.L.); (L.N.); (E.D.); (E.H.); (P.L.); (M.B.S.); (F.W.); (F.G.-C.); (A.P.-C.); (W.R.); (G.S.)
- Viral Information Institute, San Diego State University, San Diego, CA 92116, USA
- Computational Science Research Center, San Diego State University, San Diego, CA 92116, USA
- Department of Mathematics and Statistics, San Diego State University, San Diego, CA 92116, USA
| | - Muriel Ritsch
- European Virus Bioinformatics Center, 07743 Jena, Germany; (E.G.-T.); (A.J.G.); (J.G.); (D.J.); (K.K.); (A.L.); (M.R.); (G.L.L.); (L.N.); (E.D.); (E.H.); (P.L.); (M.B.S.); (F.W.); (F.G.-C.); (A.P.-C.); (W.R.); (G.S.)
- RNA Bioinformatics and High-Throughput Analysis, Friedrich Schiller University Jena, 07743 Jena, Germany;
| | - Gabriel Lencioni Lovate
- European Virus Bioinformatics Center, 07743 Jena, Germany; (E.G.-T.); (A.J.G.); (J.G.); (D.J.); (K.K.); (A.L.); (M.R.); (G.L.L.); (L.N.); (E.D.); (E.H.); (P.L.); (M.B.S.); (F.W.); (F.G.-C.); (A.P.-C.); (W.R.); (G.S.)
- RNA Bioinformatics and High-Throughput Analysis, Friedrich Schiller University Jena, 07743 Jena, Germany;
- JRG Analytical MicroBioinformatics, Friedrich Schiller University Jena, 07743 Jena, Germany
| | - Luca Nishimura
- European Virus Bioinformatics Center, 07743 Jena, Germany; (E.G.-T.); (A.J.G.); (J.G.); (D.J.); (K.K.); (A.L.); (M.R.); (G.L.L.); (L.N.); (E.D.); (E.H.); (P.L.); (M.B.S.); (F.W.); (F.G.-C.); (A.P.-C.); (W.R.); (G.S.)
- Department of Genetics, School of Life Science, The Graduate University for Advanced Studies (SOKENDAI), Mishima 411-8540, Japan
- Human Genetics Laboratory, National Institute of Genetics, Mishima 411-8540, Japan
| | - Célia Pas
- Laboratory of Applied Biotechnology, Department of Biotechnology, Ghent University, 9000 Ghent, Belgium; (D.B.); (C.P.)
| | - Esteban Domingo
- European Virus Bioinformatics Center, 07743 Jena, Germany; (E.G.-T.); (A.J.G.); (J.G.); (D.J.); (K.K.); (A.L.); (M.R.); (G.L.L.); (L.N.); (E.D.); (E.H.); (P.L.); (M.B.S.); (F.W.); (F.G.-C.); (A.P.-C.); (W.R.); (G.S.)
- Centro de Biología Molecular “Severo Ochoa” (CSIC-UAM), 28049 Madrid, Spain
- Centro de Investigación Biomédica en Red de Enfermedades Hepáticas y Digestivas (CIBERehd) del Instituto de Salud Carlos III, 28029 Madrid, Spain
| | - Emma Hodcroft
- European Virus Bioinformatics Center, 07743 Jena, Germany; (E.G.-T.); (A.J.G.); (J.G.); (D.J.); (K.K.); (A.L.); (M.R.); (G.L.L.); (L.N.); (E.D.); (E.H.); (P.L.); (M.B.S.); (F.W.); (F.G.-C.); (A.P.-C.); (W.R.); (G.S.)
- Institute of Social and Preventive Medicine, University of Bern, 3012 Bern, Switzerland
- Swiss Institute of Bioinformatics, 1015 Lausanne, Switzerland
| | - Philippe Lemey
- European Virus Bioinformatics Center, 07743 Jena, Germany; (E.G.-T.); (A.J.G.); (J.G.); (D.J.); (K.K.); (A.L.); (M.R.); (G.L.L.); (L.N.); (E.D.); (E.H.); (P.L.); (M.B.S.); (F.W.); (F.G.-C.); (A.P.-C.); (W.R.); (G.S.)
- Department of Microbiology, Immunology and Transplantation, Rega Institute, KU Leuven, 3000 Leuven, Belgium
| | - Matthew B. Sullivan
- European Virus Bioinformatics Center, 07743 Jena, Germany; (E.G.-T.); (A.J.G.); (J.G.); (D.J.); (K.K.); (A.L.); (M.R.); (G.L.L.); (L.N.); (E.D.); (E.H.); (P.L.); (M.B.S.); (F.W.); (F.G.-C.); (A.P.-C.); (W.R.); (G.S.)
- Departments of Microbiology, and Civil, Environmental, and Geodetic Engineering, Ohio State University, Columbus, OH 43210, USA
| | - Friedemann Weber
- European Virus Bioinformatics Center, 07743 Jena, Germany; (E.G.-T.); (A.J.G.); (J.G.); (D.J.); (K.K.); (A.L.); (M.R.); (G.L.L.); (L.N.); (E.D.); (E.H.); (P.L.); (M.B.S.); (F.W.); (F.G.-C.); (A.P.-C.); (W.R.); (G.S.)
- Institute for Virology, Veterinary Medicine, Justus-Liebig University, 35390 Gießen, Germany
| | - Fernando González-Candelas
- European Virus Bioinformatics Center, 07743 Jena, Germany; (E.G.-T.); (A.J.G.); (J.G.); (D.J.); (K.K.); (A.L.); (M.R.); (G.L.L.); (L.N.); (E.D.); (E.H.); (P.L.); (M.B.S.); (F.W.); (F.G.-C.); (A.P.-C.); (W.R.); (G.S.)
- Joint Research Unit “Infection and Public Health” FISABIO, University of Valencia, 46010 Valencia, Spain
- Institute for Integrative Systems Biology (I2SysBio), CSIC, University of Valencia, 46010 Valencia, Spain
| | - Sarah Krautwurst
- RNA Bioinformatics and High-Throughput Analysis, Friedrich Schiller University Jena, 07743 Jena, Germany;
| | - Alba Pérez-Cataluña
- European Virus Bioinformatics Center, 07743 Jena, Germany; (E.G.-T.); (A.J.G.); (J.G.); (D.J.); (K.K.); (A.L.); (M.R.); (G.L.L.); (L.N.); (E.D.); (E.H.); (P.L.); (M.B.S.); (F.W.); (F.G.-C.); (A.P.-C.); (W.R.); (G.S.)
- VISAFELab, Department of Preservation and Food Safety Technologies, Institute of Agrochemistry and Food Technology, IATA-CSIC, 46980 Valencia, Spain
| | - Walter Randazzo
- European Virus Bioinformatics Center, 07743 Jena, Germany; (E.G.-T.); (A.J.G.); (J.G.); (D.J.); (K.K.); (A.L.); (M.R.); (G.L.L.); (L.N.); (E.D.); (E.H.); (P.L.); (M.B.S.); (F.W.); (F.G.-C.); (A.P.-C.); (W.R.); (G.S.)
- VISAFELab, Department of Preservation and Food Safety Technologies, Institute of Agrochemistry and Food Technology, IATA-CSIC, 46980 Valencia, Spain
| | - Gloria Sánchez
- European Virus Bioinformatics Center, 07743 Jena, Germany; (E.G.-T.); (A.J.G.); (J.G.); (D.J.); (K.K.); (A.L.); (M.R.); (G.L.L.); (L.N.); (E.D.); (E.H.); (P.L.); (M.B.S.); (F.W.); (F.G.-C.); (A.P.-C.); (W.R.); (G.S.)
- VISAFELab, Department of Preservation and Food Safety Technologies, Institute of Agrochemistry and Food Technology, IATA-CSIC, 46980 Valencia, Spain
| | - Manja Marz
- European Virus Bioinformatics Center, 07743 Jena, Germany; (E.G.-T.); (A.J.G.); (J.G.); (D.J.); (K.K.); (A.L.); (M.R.); (G.L.L.); (L.N.); (E.D.); (E.H.); (P.L.); (M.B.S.); (F.W.); (F.G.-C.); (A.P.-C.); (W.R.); (G.S.)
- RNA Bioinformatics and High-Throughput Analysis, Friedrich Schiller University Jena, 07743 Jena, Germany;
| |
Collapse
|
15
|
Xu L, Li X, Gao X, Liu S, Pang Z, Wang Z. Viral suppression of type I interferon signaling by NSs proteins of DBV, SFSV and UUKV via NSs-mediated RIG-I degradation. BIOSAFETY AND HEALTH 2022. [DOI: 10.1016/j.bsheal.2022.05.004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022] Open
|
16
|
Nambou K, Anakpa M, Tong YS. Human genes with codon usage bias similar to that of the nonstructural protein 1 gene of influenza A viruses are conjointly involved in the infectious pathogenesis of influenza A viruses. Genetica 2022; 150:97-115. [PMID: 35396627 PMCID: PMC8992787 DOI: 10.1007/s10709-022-00155-9] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2021] [Accepted: 03/24/2022] [Indexed: 11/27/2022]
Abstract
Molecular mechanisms of the non-structural protein 1 (NS1) in influenza A-induced pathological changes remain ambiguous. This study explored the pathogenesis of human infection by influenza A viruses (IAVs) through identifying human genes with codon usage bias (CUB) similar to NS1 gene of these viruses based on the relative synonymous codon usage (RSCU). CUB of the IAV subtypes H1N1, H3N2, H3N8, H5N1, H5N2, H5N8, H7N9 and H9N2 was analyzed and the correlation of RSCU values of NS1 sequences with those of the human genes was calculated. The CUB of NS1 was uneven and codons ending with A/U were preferred. The ENC-GC3 and neutrality plots suggested natural selection as the main determinant for CUB. The RCDI, CAI and SiD values showed that the viruses had a high degree of adaptability to human. A total of 2155 human genes showed significant RSCU-based correlation (p < 0.05 and r > 0.5) with NS1 coding sequences and was considered as human genes with CUB similar to NS1 gene of IAV subtypes. Differences and similarities in the subtype-specific human protein–protein interaction (PPI) networks and their functions were recorded among IAVs subtypes, indicating that NS1 of each IAV subtype has a specific pathogenic mechanism. Processes and pathways involved in influenza, transcription, immune response and cell cycle were enriched in human gene sets retrieved based on the CUB of NS1 gene of IAV subtypes. The present work may advance our understanding on the mechanism of NS1 in human infections of IAV subtypes and shed light on the therapeutic options.
Collapse
Affiliation(s)
- Komi Nambou
- Shenzhen Nambou1 Biotech Company Limited, 998 Wisdom Valley, No. 38-56 Zhenming Road, Guangming District, Shenzhen, 518106, China.
| | - Manawa Anakpa
- Centre d'Informatique et de Calcul, Université de Lomé, Boulevard Gnassingbé Eyadema, 01 B.P. 1515, Lomé, Togo
| | - Yin Selina Tong
- Shenzhen Nambou1 Biotech Company Limited, 998 Wisdom Valley, No. 38-56 Zhenming Road, Guangming District, Shenzhen, 518106, China
| |
Collapse
|
17
|
Zhang Z, Bao Z, Gao P, Yao J, Wang P, Chai D. Diverse Roles of F-BoxProtein3 in Regulation of Various Cellular Functions. Front Cell Dev Biol 2022; 9:802204. [PMID: 35127719 PMCID: PMC8807484 DOI: 10.3389/fcell.2021.802204] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2021] [Accepted: 12/23/2021] [Indexed: 01/06/2023] Open
Abstract
Accumulated evidence shows that the F-box protein 3 (FBXO3) has multiple biological functions, including regulation of immune pathologies, neuropathic diseases and antiviral response. In this review article, we focus on the role of FBXO3 in inflammatory disorders and human malignancies. We also describe the substrates of FBXO3, which contribute to inflammatory disorders and cancers. We highlight that the high expression of FBXO3 is frequently observed in rheumatoid arthritis, leukemia, pituitary adenoma, and oral squamous cell carcinoma. Moreover, we discuss the regulation of FBXO3 by both carcinogens and cancer preventive agents. Our review provides a comprehensive understanding of the role of FBXO3 in various biological systems and elucidates how FBXO3 regulates substrate ubiquitination and degradation during various physiological and pathological processes. Therefore, FBXO3 can be a novel target in the treatment of human diseases including carcinomas.
Collapse
Affiliation(s)
- Zhiyang Zhang
- Department of Pathology, The First Affiliated Hospital of Bengbu Medical University, Bengbu, China
| | - Zhengqi Bao
- Department of Orthopedics, The First Affiliated Hospital of Bengbu Medical University, Bengbu, China
| | - Penglian Gao
- Department of Pathology, The First Affiliated Hospital of Bengbu Medical University, Bengbu, China
| | - Junyi Yao
- Department of Pathology, The First Affiliated Hospital of Bengbu Medical University, Bengbu, China
| | - Peter Wang
- Bengbu Medical College Key Laboratory of Cancer Research and Clinical Laboratory Diagnosis, Bengbu Medical College, Bengbu, China
- *Correspondence: Peter Wang, ; Damin Chai,
| | - Damin Chai
- Department of Pathology, The First Affiliated Hospital of Bengbu Medical University, Bengbu, China
- *Correspondence: Peter Wang, ; Damin Chai,
| |
Collapse
|
18
|
Wuerth JD, Weber F. NSs of the mildly virulent sandfly fever Sicilian virus is unable to inhibit interferon signaling and upregulation of interferon-stimulated genes. J Gen Virol 2021; 102. [PMID: 34726591 PMCID: PMC8742993 DOI: 10.1099/jgv.0.001676] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
Phleboviruses (order Bunyavirales, family Phenuiviridae) are globally emerging arboviruses with a wide spectrum of virulence. Sandfly fever Sicilian virus (SFSV) is one of the most ubiquitous members of the genus Phlebovirus and associated with a self-limited, incapacitating febrile disease in travellers and military troops. The phleboviral NSs protein is an established virulence factor, acting as antagonist of the antiviral interferon (IFN) system. Consistently, we previously reported that SFSV NSs targets the induction of IFN mRNA synthesis by specifically binding to the DNA-binding domain of the IFN transcription factor IRF3. Here, we further characterized the effect of SFSV and its NSs towards IFN induction, and evaluated its potential to affect the downstream IFN-stimulated signalling and the subsequent transactivation of antiviral interferon-stimulated genes (ISGs). We found that SFSV dampened, but did not entirely abolish type I and type III IFN induction. Furthermore, SFSV NSs did not affect IFN signalling, resulting in substantial ISG expression in infected cells. Hence, although SFSV targets IRF3 to reduce IFN induction, it is not capable of entirely disarming the IFN system in the presence of high basal IRF3 and/or IRF7 levels, and we speculate that this significantly contributes to its low level of virulence.
Collapse
Affiliation(s)
- Jennifer Deborah Wuerth
- Institute for Virology, FB10-Veterinary Medicine, Justus-Liebig University, Giessen, Germany.,Institute of Innate Immunity, University of Bonn, Bonn, Germany
| | - Friedemann Weber
- Institute for Virology, FB10-Veterinary Medicine, Justus-Liebig University, Giessen, Germany
| |
Collapse
|
19
|
Peng K, Lozach PY. Rift Valley fever virus: a new avenue of research on the biological functions of amyloids? Future Virol 2021. [DOI: 10.2217/fvl-2021-0094] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Rift Valley fever is a mosquito-borne viral zoonosis that was first discovered in the Great Rift Valley, Kenya, in 1930. Rift Valley fever virus (RVFV) primarily infects domestic animals and humans, with clinical outcomes ranging from self-limiting febrile illness to acute hepatitis and encephalitis. The virus left Africa a few decades ago, and there is a risk of introduction into southern Europe and Asia. From this perspective, we introduce RVFV and focus on the capacity of its virulence factor, the nonstructural protein NSs, to form amyloid-like fibrils. Here, we discuss the implications for the NSs biological function, the ability of RVFV to evade innate immunity, and RVFV virulence and neurotoxicity.
Collapse
Affiliation(s)
- Ke Peng
- State Key Laboratory of Virology, Wuhan Institute of Virology, Center for Biosafety Mega-Science, Chinese Academy of Sciences, Wuhan, Hubei, 430071, PR China
- University of the Chinese Academy of Sciences, Beijing, 100049, PR China
| | - Pierre-Yves Lozach
- Cell Networks, CIID (Cluster of Excellence & Center for Integrative Infectious Disease Research), Virology, University Hospital Heidelberg, 69120, Heidelberg, Germany
- University of Lyon, INRAE, EPHE, IVPC (Infections Virales et Pathologie Comparée), 69007, Lyon, France
| |
Collapse
|
20
|
Characterization of the Molecular Interactions That Govern the Packaging of Viral RNA Segments into Rift Valley Fever Phlebovirus Particles. J Virol 2021; 95:e0042921. [PMID: 33952635 DOI: 10.1128/jvi.00429-21] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Rift Valley fever phlebovirus (RVFV) has a single-stranded, negative-sense RNA genome, consisting of L, M, and S segments. The virion carries two envelope glycoproteins, Gn and Gc, along with ribonucleoprotein complexes (RNPs), composed of encapsidated genomes carrying N protein and the viral polymerase, L protein. A quantitative analysis of the profile of viral RNA segments packaged into RVFV particles showed that all three genomic RNA segments had similar packaging abilities, whereas among antigenomic RNA segments, the antigenomic S RNA, which serves as the template for the transcription of mRNA expressing the RVFV virulence factor, NSs, displayed a significantly higher packaging ability. To delineate the factor(s) governing the packaging of RVFV RNA segments, we characterized the interactions between Gn and viral RNPs in RVFV-infected cells. Coimmunoprecipitation analysis demonstrated the interaction of Gn with N protein, L protein, and viral RNAs in RVFV-infected cells. Furthermore, UV-cross-linking and immunoprecipitation analysis revealed, for the first time in bunyaviruses, the presence of a direct interaction between Gn and all the viral RNA segments in RVFV-infected cells. Notably, analysis of the ability of Gn to bind to RVFV RNA segments indicated a positive correlation with their respective packaging abilities and highlighted a binding preference of Gn for antigenomic S RNA, among the antigenomic RNA segments, suggesting the presence of a selection mechanism for antigenomic S RNA incorporation into infectious RVFV particles. Collectively, the results of our study illuminate the importance of a direct interaction between Gn and viral RNA segments in determining their efficiency of incorporation into RVFV particles. IMPORTANCE Rift Valley fever phlebovirus, a bunyavirus, is a mosquito-borne, segmented RNA virus that can cause severe disease in humans and ruminants. An essential step in RVFV life cycle is the packaging of viral RNA segments to produce infectious virus particles for dissemination to new hosts. However, there are key gaps in knowledge regarding the mechanisms that regulate viral RNA packaging efficiency in bunyaviruses. Our studies investigating the mechanism of RNA packaging in RVFV revealed the presence of a direct interaction between the viral envelope glycoprotein, Gn, and the viral RNA segments in infected cells, for the first time in bunyaviruses. Furthermore, our data strongly indicate a critical role for the direct interaction between Gn and viral RNAs in determining the efficiency of incorporation of viral RNA segments into RVFV particles. Clarifying the fundamental mechanisms of RNA packaging in RVFV would be valuable for the development of antivirals and live-attenuated vaccines.
Collapse
|
21
|
Host Cell Restriction Factors of Bunyaviruses and Viral Countermeasures. Viruses 2021; 13:v13050784. [PMID: 33925004 PMCID: PMC8146327 DOI: 10.3390/v13050784] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2021] [Revised: 04/14/2021] [Accepted: 04/20/2021] [Indexed: 01/01/2023] Open
Abstract
The Bunyavirales order comprises more than 500 viruses (generally defined as bunyaviruses) classified into 12 families. Some of these are highly pathogenic viruses infecting different hosts, including humans, mammals, reptiles, arthropods, birds, and/or plants. Host cell sensing of infection activates the innate immune system that aims at inhibiting viral replication and propagation. Upon recognition of pathogen-associated molecular patterns (PAMPs) by cellular pattern recognition receptors (PRRs), numerous signaling cascades are activated, leading to the production of interferons (IFNs). IFNs act in an autocrine and paracrine manner to establish an antiviral state by inducing the expression of hundreds of IFN-stimulated genes (ISGs). Some of these ISGs are known to restrict bunyavirus infection. Along with other constitutively expressed host cellular factors with antiviral activity, these proteins (hereafter referred to as “restriction factors”) target different steps of the viral cycle, including viral entry, genome transcription and replication, and virion egress. In reaction to this, bunyaviruses have developed strategies to circumvent this antiviral response, by avoiding cellular recognition of PAMPs, inhibiting IFN production or interfering with the IFN-mediated response. Herein, we review the current knowledge on host cellular factors that were shown to restrict infections by bunyaviruses. Moreover, we focus on the strategies developed by bunyaviruses in order to escape the antiviral state developed by the infected cells.
Collapse
|
22
|
Development of a Simian RNA Polymerase I Promoter-Driven Reverse Genetics for the Rescue of Recombinant Rift Valley Fever Virus from Vero Cells. J Virol 2021; 95:JVI.02004-20. [PMID: 33441343 PMCID: PMC8092696 DOI: 10.1128/jvi.02004-20] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Rift Valley fever (RVF), which has been designated as a priority disease by the World Health Organization (WHO), is one of the most pathogenic zoonotic diseases endemic to Africa and the Arabian Peninsula. Human vaccine preparation requires the use of appropriate cell substrates to support efficient production of seed vaccine with minimum concerns of tumorigenicity, oncogenicity, or adventitious agents. Vero cells, which were derived from the African green monkey kidney, represent one of the few mammalian cell lines that are used for vaccine manufacturing. This study demonstrated the rescue of RVFV MP-12 infectious clones in Vero cells using plasmids encoding the Macaca mulatta RNA polymerase I promoter. Although Vero cells demonstrated an approximately 20% transfection efficiency, only 0.5% of transfected cells showed the replication of viral genomic RNA, supported by the co-expression of RVFV N and L helper proteins. RVFV Infectious clones were detectable in the culture supernatants approximately 4 to 9 days posttransfection reaching maximum titers during the following 5 days. The re-amplification of rescued recombinant MP-12 (rMP-12) in Vero cells led to an increase in the genetic subpopulations, affecting the viral phenotype via amino acid substitutions in the NSs gene, whereas the rMP-12 re-amplified in human diploid MRC-5 cells did not increase viral sub-populations with NSs gene mutations. The strategy in which RVFV infectious clones are rescued in Vero cells and then subsequently amplified in MRC-5 cells will support the vaccine seed lot systems of live-attenuated recombinant RVFV vaccines for human use.IMPORTANCE RVF is a mosquito-transmitted, viral, zoonotic disease endemic to Africa and the Arabian Peninsula, and its spread outside of the endemic area will potentially cause devastating economic damages and serious public health problems. Different from classical live-attenuated vaccines, live-attenuated recombinant vaccines allow rational improvement of vaccine production efficiency, protective efficacy, and vaccine safety via the genetic engineering. This study demonstrated the generation of infectious Rift Valley fever (RVF) virus from cloned cDNA using Vero cells, which are one of a few mammalian cell lines used for vaccine manufacturing. Subsequent re-amplification of virus clones in Vero cells unexpectedly increased viral subpopulations encoding unfavorable mutations, whereas viral re-amplification in human diploid MRC-5 cells could minimize the emergence of such mutants. Rescue of recombinant RVFV from Vero cells and re-amplification in MRC-5 cells will support the vaccine seed lot systems of live-attenuated recombinant RVFV vaccines for human use.
Collapse
|
23
|
Rosche KL, Sidak-Loftis LC, Hurtado J, Fisk EA, Shaw DK. Arthropods Under Pressure: Stress Responses and Immunity at the Pathogen-Vector Interface. Front Immunol 2021; 11:629777. [PMID: 33659000 PMCID: PMC7917218 DOI: 10.3389/fimmu.2020.629777] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2020] [Accepted: 12/30/2020] [Indexed: 12/14/2022] Open
Abstract
Understanding what influences the ability of some arthropods to harbor and transmit pathogens may be key for controlling the spread of vector-borne diseases. Arthropod immunity has a central role in dictating vector competence for pathogen acquisition and transmission. Microbial infection elicits immune responses and imparts stress on the host by causing physical damage and nutrient deprivation, which triggers evolutionarily conserved stress response pathways aimed at restoring cellular homeostasis. Recent studies increasingly recognize that eukaryotic stress responses and innate immunity are closely intertwined. Herein, we describe two well-characterized and evolutionarily conserved mechanisms, the Unfolded Protein Response (UPR) and the Integrated Stress Response (ISR), and examine evidence that these stress responses impact immune signaling. We then describe how multiple pathogens, including vector-borne microbes, interface with stress responses in mammals. Owing to the well-conserved nature of the UPR and ISR, we speculate that similar mechanisms may be occurring in arthropod vectors and ultimately impacting vector competence. We conclude this Perspective by positing that novel insights into vector competence will emerge when considering that stress-signaling pathways may be influencing the arthropod immune network.
Collapse
Affiliation(s)
- Kristin L Rosche
- Program in Vector-borne Disease, Department of Veterinary Microbiology and Pathology, Washington State University, Pullman, WA, United States
| | - Lindsay C Sidak-Loftis
- Program in Vector-borne Disease, Department of Veterinary Microbiology and Pathology, Washington State University, Pullman, WA, United States
| | - Joanna Hurtado
- Program in Vector-borne Disease, Department of Veterinary Microbiology and Pathology, Washington State University, Pullman, WA, United States
| | - Elizabeth A Fisk
- Program in Vector-borne Disease, Department of Veterinary Microbiology and Pathology, Washington State University, Pullman, WA, United States
| | - Dana K Shaw
- Program in Vector-borne Disease, Department of Veterinary Microbiology and Pathology, Washington State University, Pullman, WA, United States
| |
Collapse
|
24
|
Gori Savellini G, Bini L, Gagliardi A, Anichini G, Gandolfo C, Prathyumnan S, Cusi MG. Ubiquitin and Not Only Unfolded Domains Drives Toscana Virus Non-Structural NSs Protein Degradation. Viruses 2020; 12:E1153. [PMID: 33053780 PMCID: PMC7601456 DOI: 10.3390/v12101153] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2020] [Revised: 10/05/2020] [Accepted: 10/09/2020] [Indexed: 01/09/2023] Open
Abstract
The non-structural protein NSs of the Phenuiviridae family members appears to have a role in the host immunity escape. The stability of Toscana virus (TOSV) NSs protein was tested by a cycloheximide (CHX) chase approach on cells transfected with NSs deleted versions fused to a reporter gene. The presence of intrinsically disordered regions (IDRs) both at the C- and N-terminus appeared to affect the protein stability. Indeed, the NSsΔC and NSsΔN proteins were more stable than the wild-type NSs counterpart. Since TOSV NSs exerts its inhibitory function by triggering RIG-I for proteasomal degradation, the interaction of the ubiquitin system and TOSV NSs was further examined. Chase experiments with CHX and the proteasome inhibitor MG-132 demonstrated the involvement of the ubiquitin-proteasome system in controlling NSs protein amount expressed in the cells. The analysis of TOSV NSs by mass spectrometry allowed the direct identification of K104, K109, K154, K180, K244, K294, and K298 residues targeted for ubiquitination. Analysis of NSs K-mutants confirmed the presence and the important role of lysine residues located in the central and the C-terminal parts of the protein in controlling the NSs cellular level. Therefore, we directly demonstrated a new cellular pathway involved in controlling TOSV NSs fate and activity, and this opens the way to new investigations among more pathogenic viruses of the Phenuiviridae family.
Collapse
Affiliation(s)
- Gianni Gori Savellini
- Department of Medical Biotechnologies, University of Siena, 53100 Siena, Italy; (G.A.); (C.G.); (S.P.); (M.G.C.)
| | - Luca Bini
- Department of Life Sciences, University of Siena, 53100 Siena, Italy;
| | - Assunta Gagliardi
- Department of Cellular, Computational and Integrative Biology (CIBIO), University of Trento, Laboratory of Synthetic and Structural Vaccinology, 38122 Trento, Italy;
| | - Gabriele Anichini
- Department of Medical Biotechnologies, University of Siena, 53100 Siena, Italy; (G.A.); (C.G.); (S.P.); (M.G.C.)
| | - Claudia Gandolfo
- Department of Medical Biotechnologies, University of Siena, 53100 Siena, Italy; (G.A.); (C.G.); (S.P.); (M.G.C.)
- S. Maria delle Scotte Hospital, V.le Bracci, 1, 53100 Siena, Italy
| | - Shibily Prathyumnan
- Department of Medical Biotechnologies, University of Siena, 53100 Siena, Italy; (G.A.); (C.G.); (S.P.); (M.G.C.)
| | - Maria Grazia Cusi
- Department of Medical Biotechnologies, University of Siena, 53100 Siena, Italy; (G.A.); (C.G.); (S.P.); (M.G.C.)
- S. Maria delle Scotte Hospital, V.le Bracci, 1, 53100 Siena, Italy
| |
Collapse
|
25
|
Jung S, von Thülen T, Yang I, Laukemper V, Rupf B, Janga H, Panagiotidis GD, Schoen A, Nicolai M, Schulte LN, Obermann HL, Weber F, Kaufmann A, Bauer S. A ribosomal RNA fragment with 2',3'-cyclic phosphate and GTP-binding activity acts as RIG-I ligand. Nucleic Acids Res 2020; 48:10397-10412. [PMID: 32946572 PMCID: PMC7544222 DOI: 10.1093/nar/gkaa739] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2019] [Revised: 08/19/2020] [Accepted: 08/26/2020] [Indexed: 12/13/2022] Open
Abstract
The RNA helicase RIG-I plays a key role in sensing pathogen-derived RNA. Double-stranded RNA structures bearing 5'-tri- or diphosphates are commonly referred to as activating RIG-I ligands. However, endogenous RNA fragments generated during viral infection via RNase L also activate RIG-I. Of note, RNase-digested RNA fragments bear a 5'-hydroxyl group and a 2',3'-cyclic phosphate. How endogenous RNA fragments activate RIG-I despite the lack of 5'-phosphorylation has not been elucidated. Here we describe an endogenous RIG-I ligand (eRL) that is derived from the internal transcribed spacer 2 region (ITS2) of the 45S ribosomal RNA after partial RNase A digestion in vitro, RNase A protein transfection or RNase L activation. The immunostimulatory property of the eRL is dependent on 2',3'-cyclic phosphate and its sequence is characterized by a G-quadruplex containing sequence motif mediating guanosine-5'-triphosphate (GTP) binding. In summary, RNase generated self-RNA fragments with 2',3'-cyclic phosphate function as nucleotide-5'-triphosphate binding aptamers activating RIG-I.
Collapse
Affiliation(s)
- Stephanie Jung
- Institut für Immunologie, Philipps-Universität Marburg, BMFZ, Hans-Meerwein-Straße 2, 35043 Marburg, Germany
| | - Tina von Thülen
- Institut für Immunologie, Philipps-Universität Marburg, BMFZ, Hans-Meerwein-Straße 2, 35043 Marburg, Germany
| | - Ines Yang
- Institut für Medizinische Mikrobiologie und Krankenhaushygiene, Medizinische Hochschule Hannover, Carl Neuberg Straße 1, 30625 Hannover, Germany
| | - Viktoria Laukemper
- Institut für Immunologie, Philipps-Universität Marburg, BMFZ, Hans-Meerwein-Straße 2, 35043 Marburg, Germany
| | - Benjamin Rupf
- Institut für Immunologie, Philipps-Universität Marburg, BMFZ, Hans-Meerwein-Straße 2, 35043 Marburg, Germany
| | - Harshavardhan Janga
- Institut für Lungenforschung/iLung, Philipps-Universität Marburg, BMFZ, Hans-Meerwein-Straße 2, 35043 Marburg, Germany
| | - Georgios-Dimitrios Panagiotidis
- Institut für Virologie, Fachbereich Veterinärmedizin (FB10), Justus-Liebig-Universität Gießen, Schubertstr. 81, 35392 Gießen, Germany
| | - Andreas Schoen
- Institut für Virologie, Fachbereich Veterinärmedizin (FB10), Justus-Liebig-Universität Gießen, Schubertstr. 81, 35392 Gießen, Germany
| | - Marina Nicolai
- Institut für Immunologie, Philipps-Universität Marburg, BMFZ, Hans-Meerwein-Straße 2, 35043 Marburg, Germany
| | - Leon N Schulte
- Institut für Lungenforschung/iLung, Philipps-Universität Marburg, BMFZ, Hans-Meerwein-Straße 2, 35043 Marburg, Germany
- Deutsches Zentrum für Lungenforschung (DZL), 35392 Gießen, Germany
| | - Hannah-Lena Obermann
- Institut für Immunologie, Philipps-Universität Marburg, BMFZ, Hans-Meerwein-Straße 2, 35043 Marburg, Germany
| | - Friedemann Weber
- Institut für Virologie, Fachbereich Veterinärmedizin (FB10), Justus-Liebig-Universität Gießen, Schubertstr. 81, 35392 Gießen, Germany
| | - Andreas Kaufmann
- Institut für Immunologie, Philipps-Universität Marburg, BMFZ, Hans-Meerwein-Straße 2, 35043 Marburg, Germany
| | - Stefan Bauer
- Institut für Immunologie, Philipps-Universität Marburg, BMFZ, Hans-Meerwein-Straße 2, 35043 Marburg, Germany
| |
Collapse
|
26
|
Abstract
RNA-activated protein kinase (PKR) is one of the most powerful antiviral defense factors of the mammalian host. PKR acts by phosphorylating mRNA translation initiation factor eIF2α, thereby converting it from a cofactor to an inhibitor of mRNA translation that strongly binds to initiation factor eIF2B. To sustain synthesis of their proteins, viruses are known to counteract this on the level of PKR or eIF2α or by circumventing initiation factor-dependent translation altogether. Here, we report a different PKR escape strategy executed by sandfly fever Sicilian virus (SFSV), a member of the increasingly important group of phleboviruses. We found that the nonstructural protein NSs of SFSV binds to eIF2B and protects it from inactivation by PKR-generated phospho-eIF2α. Protein synthesis is hence maintained and the virus can replicate despite ongoing full-fledged PKR signaling in the infected cells. Thus, SFSV has evolved a unique strategy to escape the powerful antiviral PKR. RNA-activated protein kinase (PKR) is a major innate immune factor that senses viral double-stranded RNA (dsRNA) and phosphorylates eukaryotic initiation factor (eIF) 2α. Phosphorylation of the α subunit converts the eIF2αβγ complex into a stoichiometric inhibitor of eukaryotic initiation factor eIF2B, thus halting mRNA translation. To escape this protein synthesis shutoff, viruses have evolved countermechanisms such as dsRNA sequestration, eIF-independent translation by an internal ribosome binding site, degradation of PKR, or dephosphorylation of PKR or of phospho-eIF2α. Here, we report that sandfly fever Sicilian phlebovirus (SFSV) confers such a resistance without interfering with PKR activation or eIF2α phosphorylation. Rather, SFSV expresses a nonstructural protein termed NSs that strongly binds to eIF2B. Although NSs still allows phospho-eIF2α binding to eIF2B, protein synthesis and virus replication are unhindered. Hence, SFSV encodes a unique PKR antagonist that acts by rendering eIF2B resistant to the inhibitory action of bound phospho-eIF2α.
Collapse
|
27
|
Lau S, Weber F. Nuclear pore protein Nup98 is involved in replication of Rift Valley fever virus and nuclear import of virulence factor NSs. J Gen Virol 2020; 101:712-716. [PMID: 31671053 PMCID: PMC7660236 DOI: 10.1099/jgv.0.001347] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2019] [Accepted: 10/01/2019] [Indexed: 12/17/2022] Open
Abstract
The non-structural protein NSs is the main virulence factor of Rift Valley fever virus, a major zoonotic pathogen in Africa. NSs forms large aggregates in the nucleus and impairs induction of the antiviral type I IFN system by several mechanisms, including degradation of subunit p62 of the general RNA polymerase II transcription factor TFIIH. Here, we show that depletion of the nuclear pore protein Nup98 affects the nuclear import of NSs. Nonetheless, NSs was still able to degrade TFIIH-p62 under these conditions. Depletion of Nup98, however, had a negative effect on Rift Valley fever virus multiplication. Our data thus indicate that NSs utilizes Nup98 for import into the nucleus, but also plays a general role in the viral replication cycle.
Collapse
Affiliation(s)
- Simone Lau
- Institute for Virology, FB10-Veterinary Medicine, Justus-Liebig University, D-35392 Giessen, Germany
- Institute for Virology, Philipps-University Marburg, D-35043 Marburg, Germany
| | - Friedemann Weber
- Institute for Virology, FB10-Veterinary Medicine, Justus-Liebig University, D-35392 Giessen, Germany
- Institute for Virology, Philipps-University Marburg, D-35043 Marburg, Germany
- German Center for Infection Research (DZIF), partner sites Marburg and Giessen, Germany
| |
Collapse
|
28
|
Elongin C Contributes to RNA Polymerase II Degradation by the Interferon Antagonist NSs of La Crosse Orthobunyavirus. J Virol 2020; 94:JVI.02134-19. [PMID: 31941775 PMCID: PMC7081911 DOI: 10.1128/jvi.02134-19] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2019] [Accepted: 12/26/2019] [Indexed: 12/21/2022] Open
Abstract
The mosquito-borne La Crosse virus (LACV; genus Orthobunyavirus, family Peribunyaviridae, order Bunyavirales) is prevalent in the United States and can cause severe childhood meningoencephalitis. Its main virulence factor, the nonstructural protein NSs, is a strong inhibitor of the antiviral type I interferon (IFN) system. NSs acts by imposing a global host mRNA synthesis shutoff, mediated by NSs-driven proteasomal degradation of the RPB1 subunit of RNA polymerase II. Here, we show that RPB1 degradation commences as early as 1 h postinfection, and identify the E3 ubiquitin ligase subunit Elongin C (and its binding partners Elongins A and B) as an NSs cofactor involved in RPB1 degradation and in suppression of global as well as IFN-related mRNA synthesis. Mosquito-borne La Crosse virus (LACV; genus Orthobunyavirus, family Peribunyaviridae, order Bunyavirales) causes up to 100 annual cases of severe meningoencephalitis in children and young adults in the United States. A major virulence factor of LACV is the nonstructural protein NSs, which inhibits host cell mRNA synthesis to prevent the induction of antiviral type I interferons (IFN-α/β). To achieve this host transcriptional shutoff, LACV NSs drives the proteasomal degradation of RPB1, the large subunit of mammalian RNA polymerase II. Here, we show that NSs acts in a surprisingly rapid manner, as RPB1 degradation was commencing already at 1 h postinfection. The RPB1 degradation was partially dependent on the cellular E3 ubiquitin ligase subunit Elongin C. Consequently, removal of Elongin C, but also of the subunits Elongin A or B by siRNA transfection partially rescued general RNAP II transcription and IFN-beta mRNA synthesis from the blockade by NSs. In line with these results, LACV NSs was found to trigger the redistribution of Elongin C out of nucleolar speckles, which, however, is an epiphenomenon rather than part of the NSs mechanism. Our study also shows that the molecular phenotype of LACV NSs is different from RNA polymerase II inhibitors like α-amanitin or Rift Valley fever virus NSs, indicating that LACV is unique in involving the Elongin complex to shut off host transcription and IFN response. IMPORTANCE The mosquito-borne La Crosse virus (LACV; genus Orthobunyavirus, family Peribunyaviridae, order Bunyavirales) is prevalent in the United States and can cause severe childhood meningoencephalitis. Its main virulence factor, the nonstructural protein NSs, is a strong inhibitor of the antiviral type I interferon (IFN) system. NSs acts by imposing a global host mRNA synthesis shutoff, mediated by NSs-driven proteasomal degradation of the RPB1 subunit of RNA polymerase II. Here, we show that RPB1 degradation commences as early as 1 h postinfection, and identify the E3 ubiquitin ligase subunit Elongin C (and its binding partners Elongins A and B) as an NSs cofactor involved in RPB1 degradation and in suppression of global as well as IFN-related mRNA synthesis.
Collapse
|
29
|
Gori Savellini G, Anichini G, Gandolfo C, Prathyumnan S, Cusi MG. Toscana virus non-structural protein NSs acts as E3 ubiquitin ligase promoting RIG-I degradation. PLoS Pathog 2019; 15:e1008186. [PMID: 31815967 PMCID: PMC6901176 DOI: 10.1371/journal.ppat.1008186] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2019] [Accepted: 11/04/2019] [Indexed: 01/04/2023] Open
Abstract
It is known that the non-structural protein (NSs) of Toscana virus (TOSV), an emergent sandfly-borne virus causing meningitis or more severe central nervous system injuries in humans, exerts its function triggering RIG-I for degradation in a proteasome-dependent manner, thus breaking off the IFN-β production. The non-structural protein of different members of Bunyavirales has recently appeared as a fundamental protagonist in immunity evasion through ubiquitination-mediated protein degradation targets. We showed that TOSV NSs has an E3 ubiquitin ligase activity, mapping at the carboxy-terminal domain and also involving the amino-terminal of the protein. Indeed, neither the amino- (NSsΔN) nor the carboxy- (NSsΔC) terminal-deleted mutants of TOSV NSs were able to cause ubiquitin-mediated proteasome degradation of RIG-I. Moreover, the addition of the C-terminus of TOSV NSs to the homologous protein of the Sandfly Fever Naples Virus, belonging to the same genus and unable to inhibit IFN-β activity, conferred new properties to this protein, favoring RIG-I ubiquitination and its degradation. NSs lost its antagonistic activity to IFN when one of the terminal residues was missing. Therefore, we showed that NSs could behave as an atypical RING between RING (RBR) E3 ubiquitin ligases. This is the first report which identified the E3 ubiquitin ligase activity in a viral protein among negative strand RNA viruses.
Collapse
Affiliation(s)
| | - Gabriele Anichini
- Department of Medical Biotechnologies, University of Siena, Siena, Italy
| | - Claudia Gandolfo
- Department of Medical Biotechnologies, University of Siena, Siena, Italy
| | | | - Maria Grazia Cusi
- Department of Medical Biotechnologies, University of Siena, Siena, Italy
| |
Collapse
|
30
|
Hallam HJ, Lokugamage N, Ikegami T. Rescue of infectious Arumowot virus from cloned cDNA: Posttranslational degradation of Arumowot virus NSs protein in human cells. PLoS Negl Trop Dis 2019; 13:e0007904. [PMID: 31751340 PMCID: PMC6894884 DOI: 10.1371/journal.pntd.0007904] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2019] [Revised: 12/05/2019] [Accepted: 11/04/2019] [Indexed: 12/11/2022] Open
Abstract
Rift Valley fever (RVF) is a mosquito-borne zoonotic disease endemic to Africa and the Middle East, affecting both humans and ruminants. There are no licensed vaccines or antivirals available for humans, whereas research using RVF virus (RVFV) is strictly regulated in many countries with safety concerns. Nonpathogenic Arumowot virus (AMTV), a mosquito-borne phlebovirus in Africa, is likely useful for the screening of broad-acting antiviral candidates for phleboviruses including RVFV, as well as a potential vaccine vector for RVF. In this study, we aimed to generate T7 RNA polymerase-driven reverse genetics system for AMTV. We hypothesized that recombinant AMTV (rAMTV) is viable, and AMTV NSs protein is dispensable for efficient replication of rAMTV in type-I interferon (IFN)-incompetent cells, whereas AMTV NSs proteins support robust viral replication in type-I IFN-competent cells. The study demonstrated the rescue of rAMTV and that lacking the NSs gene (rAMTVΔNSs), that expressing green fluorescent protein (GFP) (rAMTV-GFP) or that expressing Renilla luciferase (rAMTV-rLuc) from cloned cDNA. The rAMTV-rLuc and the RVFV rMP12-rLuc showed a similar susceptibility to favipiravir or ribavirin. Interestingly, neither of rAMTV nor rAMTVΔNSs replicated efficiently in human MRC-5 or A549 cells, regardless of the presence of NSs gene. Little accumulation of AMTV NSs protein occurred in those cells, which was restored via treatment with proteasomal inhibitor MG132. In murine MEF or Hepa1-6 cells, rAMTV, but not rAMTVΔNSs, replicated efficiently, with an inhibition of IFN-β gene upregulation. This study showed an establishment of the first reverse genetics for AMTV, a lack of stability of AMTV NSs proteins in human cells, and an IFN-β gene antagonist function of AMTV NSs proteins in murine cells. The AMTV can be a nonpathogenic surrogate model for studying phleboviruses including RVFV.
Collapse
Affiliation(s)
- Hoai J. Hallam
- Department of Pathology, The University of Texas Medical Branch at Galveston, Galveston, Texas, United States of America
| | - Nandadeva Lokugamage
- Department of Pathology, The University of Texas Medical Branch at Galveston, Galveston, Texas, United States of America
| | - Tetsuro Ikegami
- Department of Pathology, The University of Texas Medical Branch at Galveston, Galveston, Texas, United States of America
- Sealy Institute for Vaccine Sciences, The University of Texas Medical Branch at Galveston, Galveston, Texas, United States of America
- Center for Biodefense and Emerging Infectious Diseases, The University of Texas Medical Branch at Galveston, Galveston, Texas, United States of America
- * E-mail:
| |
Collapse
|
31
|
Terasaki K, Juelich TL, Smith JK, Kalveram B, Perez DD, Freiberg AN, Makino S. A single-cycle replicable Rift Valley fever phlebovirus vaccine carrying a mutated NSs confers full protection from lethal challenge in mice. Sci Rep 2018; 8:17097. [PMID: 30459418 PMCID: PMC6244155 DOI: 10.1038/s41598-018-35472-7] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2018] [Accepted: 11/05/2018] [Indexed: 11/09/2022] Open
Abstract
Rift Valley fever phlebovirus (RVFV) is a pathogen of Rift Valley fever, which is a mosquito-borne zoonotic disease for domestic livestock and humans in African countries. Currently, no approved vaccine is available for use in non-endemic areas. The MP-12 strain is so far the best live attenuated RVFV vaccine candidate because of its good protective efficacy in animal models. However, there are safety concerns for use of MP-12 in humans. We previously developed a single-cycle replicable MP-12 (scMP-12) which lacks NSs gene and undergoes only a single round of viral replication because of its impaired ability to induce membrane-membrane fusion. In the present study, we generated an scMP-12 mutant (scMP-12-mutNSs) carrying a mutant NSs, which degrades double-stranded RNA-dependent protein kinase R but does not inhibit host transcription. Immunization of mice with a single dose (105 PFU) of scMP-12-mutNSs elicited RVFV neutralizing antibodies and high titers of anti-N IgG production and fully protected the mice from lethal wild-type RVFV challenge. Immunogenicity and protective efficacy of scMP-12-mutNSs were better than scMP-12, demonstrating that scMP-12-mutNSs is a more efficacious vaccine candidate than scMP-12. Furthermore, our data suggested that RVFV vaccine efficacy can be improved by using this specific NSs mutant.
Collapse
Affiliation(s)
- Kaori Terasaki
- Department of Microbiology and Immunology, The University of Texas Medical Branch, Galveston, Texas, 77555-1019, United States.,Institute for Human Infection and Immunity, The University of Texas Medical Branch, Galveston, Texas, 77555-1019, United States
| | - Terry L Juelich
- Department of Pathology, The University of Texas Medical Branch, Galveston, Texas, 77555-1019, United States
| | - Jennifer K Smith
- Department of Pathology, The University of Texas Medical Branch, Galveston, Texas, 77555-1019, United States
| | - Birte Kalveram
- Department of Pathology, The University of Texas Medical Branch, Galveston, Texas, 77555-1019, United States
| | - David D Perez
- Department of Pathology, The University of Texas Medical Branch, Galveston, Texas, 77555-1019, United States
| | - Alexander N Freiberg
- Department of Pathology, The University of Texas Medical Branch, Galveston, Texas, 77555-1019, United States.,Center for Biodefense and Emerging Infectious Diseases, The University of Texas Medical Branch, Galveston, Texas, 77555-1019, United States.,UTMB Center for Tropical Diseases, The University of Texas Medical Branch, Galveston, Texas, 77555-1019, United States.,The Sealy Institute for Vaccine Sciences, The University of Texas Medical Branch, Galveston, Texas, 77555-1019, United States.,Institute for Human Infection and Immunity, The University of Texas Medical Branch, Galveston, Texas, 77555-1019, United States
| | - Shinji Makino
- Department of Microbiology and Immunology, The University of Texas Medical Branch, Galveston, Texas, 77555-1019, United States. .,Center for Biodefense and Emerging Infectious Diseases, The University of Texas Medical Branch, Galveston, Texas, 77555-1019, United States. .,UTMB Center for Tropical Diseases, The University of Texas Medical Branch, Galveston, Texas, 77555-1019, United States. .,The Sealy Institute for Vaccine Sciences, The University of Texas Medical Branch, Galveston, Texas, 77555-1019, United States. .,Institute for Human Infection and Immunity, The University of Texas Medical Branch, Galveston, Texas, 77555-1019, United States.
| |
Collapse
|
32
|
Molecular aspects of Rift Valley fever virus and the emergence of reassortants. Virus Genes 2018; 55:1-11. [PMID: 30426314 DOI: 10.1007/s11262-018-1611-y] [Citation(s) in RCA: 32] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2018] [Accepted: 11/03/2018] [Indexed: 10/27/2022]
Abstract
Rift Valley fever phlebovirus (RVFV) is a mosquito-transmitted pathogen endemic to sub-Saharan Africa and the Arabian Peninsula. RVFV is a threat to both animal and human health and has costly economic consequences mainly related to livestock production and trade. Competent hosts and vectors for RVFV are widespread, existing outside of endemic countries including the USA. Thus, the possibility of RVFV spreading to the USA or other countries worldwide is of significant concern. RVFV (genus Phlebovirus) is comprised of an enveloped virion containing a three-segmented, negative-stranded RNA genome that is able to undergo genetic reassortment. Reassortment has the potential to produce viruses that are more pathogenic, easily transmissible, and that have wider vector or host range. This is especially concerning because of the wide use of live attenuated vaccine strains throughout endemic countries. This review focuses on the molecular aspects of RVFV, genetic diversity of RVFV strains, and RVFV reassortment.
Collapse
|
33
|
NSs Protein of Sandfly Fever Sicilian Phlebovirus Counteracts Interferon (IFN) Induction by Masking the DNA-Binding Domain of IFN Regulatory Factor 3. J Virol 2018; 92:JVI.01202-18. [PMID: 30232186 PMCID: PMC6232482 DOI: 10.1128/jvi.01202-18] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2018] [Accepted: 09/13/2018] [Indexed: 12/25/2022] Open
Abstract
Sandfly fever Sicilian virus (SFSV) is one of the most widespread and frequently identified members of the genus Phlebovirus (order Bunyavirales, family Phenuiviridae) infecting humans. Being transmitted by Phlebotomus sandflies, SFSV causes a self-limiting, acute, often incapacitating febrile disease ("sandfly fever," "Pappataci fever," or "dog disease") that has been known since at least the beginning of the 20th century. We show that, similarly to other pathogenic phleboviruses, SFSV suppresses the induction of the antiviral type I interferon (IFN) system in an NSs-dependent manner. SFSV NSs interfered with the TBK1-interferon regulatory factor 3 (IRF3) branch of the RIG-I signaling pathway but not with NF-κB activation. Consistently, we identified IRF3 as a host interactor of SFSV NSs. In contrast to IRF3, neither the IFN master regulator IRF7 nor any of the related transcription factors IRF2, IRF5, and IRF9 were bound by SFSV NSs. In spite of this specificity for IRF3, NSs did not inhibit its phosphorylation, dimerization, or nuclear accumulation, and the interaction was independent of the IRF3 activation or multimerization state. In further studies, we identified the DNA-binding domain of IRF3 (amino acids 1 to 113) as sufficient for NSs binding and found that SFSV NSs prevented the association of activated IRF3 with the IFN-β promoter. Thus, unlike highly virulent phleboviruses, which either destroy antiviral host factors or sequester whole signaling chains into inactive aggregates, SFSV modulates type I IFN induction by directly masking the DNA-binding domain of IRF3.IMPORTANCE Phleboviruses are receiving increased attention due to the constant discovery of new species and the ongoing spread of long-known members of the genus. Outbreaks of sandfly fever were reported in the 19th century, during World War I, and during World War II. Currently, SFSV is recognized as one of the most widespread phleboviruses, exhibiting high seroprevalence rates in humans and domestic animals and causing a self-limiting but incapacitating disease predominantly in immunologically naive troops and travelers. We show how the nonstructural NSs protein of SFSV counteracts the upregulation of the antiviral interferon (IFN) system. SFSV NSs specifically inhibits promoter binding by IFN transcription factor 3 (IRF3), a molecular strategy which is unique among phleboviruses and, to our knowledge, among human pathogenic RNA viruses in general. This IRF3-specific and stoichiometric mechanism, greatly distinct from the ones exhibited by the highly virulent phleboviruses, correlates with the intermediate level of pathogenicity of SFSV.
Collapse
|
34
|
Pinkham C, Ahmed A, Bracci N, Narayanan A, Kehn-Hall K. Host-based processes as therapeutic targets for Rift Valley fever virus. Antiviral Res 2018; 160:64-78. [PMID: 30316916 DOI: 10.1016/j.antiviral.2018.10.004] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2018] [Revised: 09/27/2018] [Accepted: 10/05/2018] [Indexed: 12/28/2022]
Abstract
Rift Valley fever virus (RVFV) is an enveloped, segmented, negative sense RNA virus that replicates within the host's cytoplasm. To facilitate its replication, RVFV must utilize host cell processes and as such, these processes may serve as potential therapeutic targets. This review summarizes key host cell processes impacted by RVFV infection. Specifically the influence of RVFV on host transcriptional regulation, post-transcriptional regulation, protein half-life and availability, host signal transduction, trafficking and secretory pathways, cytoskeletal modulation, and mitochondrial processes and oxidative stress are discussed. Therapeutics targeted towards host processes that are essential for RVFV to thrive as well as their efficacy and importance to viral pathogenesis are highlighted.
Collapse
Affiliation(s)
- Chelsea Pinkham
- National Center for Biodefense and Infectious Diseases, School of Systems Biology, George Mason University, Manassas, VA, USA
| | - Aslaa Ahmed
- National Center for Biodefense and Infectious Diseases, School of Systems Biology, George Mason University, Manassas, VA, USA
| | - Nicole Bracci
- National Center for Biodefense and Infectious Diseases, School of Systems Biology, George Mason University, Manassas, VA, USA
| | - Aarthi Narayanan
- National Center for Biodefense and Infectious Diseases, School of Systems Biology, George Mason University, Manassas, VA, USA
| | - Kylene Kehn-Hall
- National Center for Biodefense and Infectious Diseases, School of Systems Biology, George Mason University, Manassas, VA, USA.
| |
Collapse
|
35
|
Haas DA, Meiler A, Geiger K, Vogt C, Preuss E, Kochs G, Pichlmair A. Viral targeting of TFIIB impairs de novo polymerase II recruitment and affects antiviral immunity. PLoS Pathog 2018; 14:e1006980. [PMID: 29709033 PMCID: PMC5927403 DOI: 10.1371/journal.ppat.1006980] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2017] [Accepted: 03/19/2018] [Indexed: 11/21/2022] Open
Abstract
Viruses have evolved a plethora of mechanisms to target host antiviral responses. Here, we propose a yet uncharacterized mechanism of immune regulation by the orthomyxovirus Thogoto virus (THOV) ML protein through engaging general transcription factor TFIIB. ML generates a TFIIB depleted nuclear environment by re-localizing it into the cytoplasm. Although a broad effect on gene expression would be anticipated, ML expression, delivery of an ML-derived functional domain or experimental depletion of TFIIB only leads to altered expression of a limited number of genes. Our data indicate that TFIIB is critically important for the de novo recruitment of Pol II to promoter start sites and that TFIIB may not be required for regulated gene expression from paused promoters. Since many immune genes require de novo recruitment of Pol II, targeting of TFIIB by THOV represents a neat mechanism to affect immune responses while keeping other cellular transcriptional activities intact. Thus, interference with TFIIB activity may be a favourable site for therapeutic intervention to control undesirable inflammation. Viruses target the innate immune system at critical vulnerability points. Here we show that the orthomyxovirus Thogoto virus impairs activity of general transcription factor IIB (TFIIB). Surprisingly, impairment of TFIIB function does not result in a general inhibition of transcription but in a rather specific impairment of selective genes. Transcriptome and functional analyses intersected with published CHIP-Seq datasets suggest that affected genes require de novo recruitment of the polymerase complex. Since the innate immune system heavily relies on genes that require de novo recruitment of the polymerase complex, targeting of TFIIB represents a neat mechanism to broadly affect antiviral immunity. Conversely, therapeutic targeting of TFIIB may represent a mechanism to limit pathological side effects caused by overshooting immune reactions.
Collapse
Affiliation(s)
- Darya A. Haas
- Innate Immunity Laboratory, Max-Planck Institute of Biochemistry, Martinsried/Munich, Germany
| | - Arno Meiler
- Innate Immunity Laboratory, Max-Planck Institute of Biochemistry, Martinsried/Munich, Germany
| | - Katharina Geiger
- Institute of Virology, Medical Center—University of Freiburg, Freiburg, Germany
| | - Carola Vogt
- Institute of Virology, Medical Center—University of Freiburg, Freiburg, Germany
| | - Ellen Preuss
- Institute of Virology, Medical Center—University of Freiburg, Freiburg, Germany
| | - Georg Kochs
- Institute of Virology, Medical Center—University of Freiburg, Freiburg, Germany
- Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - Andreas Pichlmair
- Innate Immunity Laboratory, Max-Planck Institute of Biochemistry, Martinsried/Munich, Germany
- Technical University of Munich, School of Medicine, Institute of Virology, Munich, Germany
- German Center for Infection Research (DZIF), Munich partner site, Munich, Germany
- * E-mail:
| |
Collapse
|
36
|
de la Fuente C, Pinkham C, Dabbagh D, Beitzel B, Garrison A, Palacios G, Hodge KA, Petricoin EF, Schmaljohn C, Campbell CE, Narayanan A, Kehn-Hall K. Phosphoproteomic analysis reveals Smad protein family activation following Rift Valley fever virus infection. PLoS One 2018; 13:e0191983. [PMID: 29408900 PMCID: PMC5800665 DOI: 10.1371/journal.pone.0191983] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2017] [Accepted: 01/15/2018] [Indexed: 01/07/2023] Open
Abstract
Rift Valley fever virus (RVFV) infects both ruminants and humans leading to a wide variance of pathologies dependent on host background and age. Utilizing a targeted reverse phase protein array (RPPA) to define changes in signaling cascades after in vitro infection of human cells with virulent and attenuated RVFV strains, we observed high phosphorylation of Smad transcription factors. This evolutionarily conserved family is phosphorylated by and transduces the activation of TGF-β superfamily receptors. Moreover, we observed that phosphorylation of Smad proteins required active RVFV replication and loss of NSs impaired this activation, further corroborating the RPPA results. Gene promoter analysis of transcripts altered after RVFV infection identified 913 genes that contained a Smad-response element. Functional annotation of these potential Smad-regulated genes clustered in axonal guidance, hepatic fibrosis and cell signaling pathways involved in cellular adhesion/migration, calcium influx, and cytoskeletal reorganization. Furthermore, chromatin immunoprecipitation confirmed the presence of a Smad complex on the interleukin 1 receptor type 2 (IL1R2) promoter, which acts as a decoy receptor for IL-1 activation.
Collapse
Affiliation(s)
- Cynthia de la Fuente
- National Center for Biodefense and Infectious Diseases, School of Systems Biology, George Mason University, Manassas, Virginia, United States of America
| | - Chelsea Pinkham
- National Center for Biodefense and Infectious Diseases, School of Systems Biology, George Mason University, Manassas, Virginia, United States of America
| | - Deemah Dabbagh
- National Center for Biodefense and Infectious Diseases, School of Systems Biology, George Mason University, Manassas, Virginia, United States of America
| | - Brett Beitzel
- United States Army Medical Research Institute of Infectious Diseases, Frederick, Maryland, United States of America
| | - Aura Garrison
- United States Army Medical Research Institute of Infectious Diseases, Frederick, Maryland, United States of America
| | - Gustavo Palacios
- United States Army Medical Research Institute of Infectious Diseases, Frederick, Maryland, United States of America
| | - Kimberley Alex Hodge
- Center for Applied Proteomics and Molecular Medicine, School of Systems Biology, George Mason University, Manassas, Virginia, United States of America
| | - Emanuel F. Petricoin
- Center for Applied Proteomics and Molecular Medicine, School of Systems Biology, George Mason University, Manassas, Virginia, United States of America
| | - Connie Schmaljohn
- United States Army Medical Research Institute of Infectious Diseases, Frederick, Maryland, United States of America
| | | | - Aarthi Narayanan
- National Center for Biodefense and Infectious Diseases, School of Systems Biology, George Mason University, Manassas, Virginia, United States of America
| | - Kylene Kehn-Hall
- National Center for Biodefense and Infectious Diseases, School of Systems Biology, George Mason University, Manassas, Virginia, United States of America
- * E-mail:
| |
Collapse
|
37
|
Alterations in the host transcriptome in vitro following Rift Valley fever virus infection. Sci Rep 2017; 7:14385. [PMID: 29085037 PMCID: PMC5662566 DOI: 10.1038/s41598-017-14800-3] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2017] [Accepted: 10/16/2017] [Indexed: 01/01/2023] Open
Abstract
Rift Valley fever virus (RVFV) causes major outbreaks among livestock, characterized by "abortion storms" in which spontaneous abortion occurs in almost 100% of pregnant ruminants. Humans can also become infected with mild symptoms that can progress to more severe symptoms, such as hepatitis, encephalitis, and hemorrhagic fever. The goal of this study was to use RNA-sequencing (RNA-seq) to analyze the host transcriptome in response to RVFV infection. G2/M DNA damage checkpoint, ATM signaling, mitochondrial dysfunction, regulation of the antiviral response, and integrin-linked kinase (ILK) signaling were among the top altered canonical pathways with both the attenuated MP12 strain and the fully virulent ZH548 strain. Although several mRNA transcripts were highly upregulated, an increase at the protein level was not observed for the selected genes, which was at least partially due to the NSs dependent block in mRNA export. Inhibition of ILK signaling, which is involved in cell motility and cytoskeletal reorganization, resulted in reduced RVFV replication, indicating that this pathway is important for viral replication. Overall, this is the first global transcriptomic analysis of the human host response following RVFV infection, which could give insight into novel host responses that have not yet been explored.
Collapse
|
38
|
Barski M, Brennan B, Miller OK, Potter JA, Vijayakrishnan S, Bhella D, Naismith JH, Elliott RM, Schwarz-Linek U. Rift Valley fever phlebovirus NSs protein core domain structure suggests molecular basis for nuclear filaments. eLife 2017; 6. [PMID: 28915104 PMCID: PMC5601994 DOI: 10.7554/elife.29236] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2017] [Accepted: 08/21/2017] [Indexed: 12/24/2022] Open
Abstract
Rift Valley fever phlebovirus (RVFV) is a clinically and economically important pathogen increasingly likely to cause widespread epidemics. RVFV virulence depends on the interferon antagonist non-structural protein (NSs), which remains poorly characterized. We identified a stable core domain of RVFV NSs (residues 83–248), and solved its crystal structure, a novel all-helical fold organized into highly ordered fibrils. A hallmark of RVFV pathology is NSs filament formation in infected cell nuclei. Recombinant virus encoding the NSs core domain induced intranuclear filaments, suggesting it contains all essential determinants for nuclear translocation and filament formation. Mutations of key crystal fibril interface residues in viruses encoding full-length NSs completely abrogated intranuclear filament formation in infected cells. We propose the fibrillar arrangement of the NSs core domain in crystals reveals the molecular basis of assembly of this key virulence factor in cell nuclei. Our findings have important implications for fundamental understanding of RVFV virulence. Rift Valley fever phlebovirus (RVFV) is a virus of humans and livestock, transmitted by mosquitos and contact with infected animals. Infection can cause severe disease, including hemorrhagic fever, and may lead to death. Historically, the virus was only found in central Africa but it has spread for instance to the Arabian Peninsula. There is a risk that the virus may appear in temperate regions including Europe because global warming is allowing the mosquitos that carry the virus to extend their geographic range. There are no vaccines or treatments available for use in humans so if there is a serious outbreak of the virus it could become an epidemic and cause great economic losses and severe human disease. RVFV relies on a protein called NSs to cause disease. In cells of infected animals and humans NSs forms filaments inside the nucleus, the control center of the cell, and disarms the immune system. However, it is not known precisely how NSs works. To address this question, Barski, Brennan et al. used a technique called X-ray crystallography to study the atomic three-dimensional structure of NSs. This revealed that the center of the protein contains a core domain that causes the filaments to form. Further experiments identified how the NSs core comes together to build the filaments inside the cell nucleus. These findings represent an important step towards understanding how the NSs protein helps RVFV to cause disease in humans and livestock. In the future, this work may aid the development of much needed drugs and vaccines against RVFV.
Collapse
Affiliation(s)
- Michal Barski
- Biomedical Sciences Research Complex, University of St Andrews, St Andrews, United Kingdom
| | - Benjamin Brennan
- MRC-University of Glasgow Centre for Virus Research, London, United Kingdom
| | - Ona K Miller
- Biomedical Sciences Research Complex, University of St Andrews, St Andrews, United Kingdom
| | - Jane A Potter
- Biomedical Sciences Research Complex, University of St Andrews, St Andrews, United Kingdom
| | | | - David Bhella
- MRC-University of Glasgow Centre for Virus Research, London, United Kingdom
| | - James H Naismith
- Biomedical Sciences Research Complex, University of St Andrews, St Andrews, United Kingdom
| | - Richard M Elliott
- MRC-University of Glasgow Centre for Virus Research, London, United Kingdom
| | - Ulrich Schwarz-Linek
- Biomedical Sciences Research Complex, University of St Andrews, St Andrews, United Kingdom
| |
Collapse
|
39
|
Pan W, Song D, He W, Lu H, Lan Y, Tong J, Gao F, Zhao K. The matrix protein of vesicular stomatitis virus inhibits host-directed transcription of target genes via interaction with the TFIIH subunit p8. Vet Microbiol 2017; 208:82-88. [DOI: 10.1016/j.vetmic.2017.07.020] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2017] [Revised: 07/16/2017] [Accepted: 07/18/2017] [Indexed: 10/19/2022]
|
40
|
Mapping of Transcription Termination within the S Segment of SFTS Phlebovirus Facilitated Generation of NSs Deletant Viruses. J Virol 2017; 91:JVI.00743-17. [PMID: 28592543 PMCID: PMC5533932 DOI: 10.1128/jvi.00743-17] [Citation(s) in RCA: 31] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2017] [Accepted: 05/31/2017] [Indexed: 12/15/2022] Open
Abstract
SFTS phlebovirus (SFTSV) is an emerging tick-borne bunyavirus that was first reported in China in 2009. Here we report the generation of a recombinant SFTSV (rHB29NSsKO) that cannot express the viral nonstructural protein (NSs) upon infection of cells in culture. We show that rHB29NSsKO replication kinetics are greater in interferon (IFN)-incompetent cells and that the virus is unable to suppress IFN induced in response to viral replication. The data confirm for the first time in the context of virus infection that NSs acts as a virally encoded IFN antagonist and that NSs is dispensable for virus replication. Using 3' rapid amplification of cDNA ends (RACE), we mapped the 3' end of the N and NSs mRNAs, showing that the mRNAs terminate within the coding region of the opposite open reading frame. We show that the 3' end of the N mRNA terminates upstream of a 5'-GCCAGCC-3' motif present in the viral genomic RNA. With this knowledge, and using virus-like particles, we could demonstrate that the last 36 nucleotides of the NSs open reading frame (ORF) were needed to ensure the efficient termination of the N mRNA and were required for recombinant virus rescue. We demonstrate that it is possible to recover viruses lacking NSs (expressing just a 12-amino-acid NSs peptide or encoding enhanced green fluorescent protein [eGFP]) or an NSs-eGFP fusion protein in the NSs locus. This opens the possibility for further studies of NSs and potentially the design of attenuated viruses for vaccination studies.IMPORTANCE SFTS phlebovirus (SFTSV) and related tick-borne viruses have emerged globally since 2009. SFTSV has been shown to cause severe disease in humans. For bunyaviruses, it has been well documented that the nonstructural protein (NSs) enables the virus to counteract the human innate antiviral defenses and that NSs is one of the major determinants of virulence in infection. Therefore, the use of reverse genetics systems to engineer viruses lacking NSs is an attractive strategy to rationally attenuate bunyaviruses. Here we report the generation of several recombinant SFTS viruses that cannot express the NSs protein or have the NSs open reading frame replaced with a reporter gene. These viruses cannot antagonize the mammalian interferon (IFN) response mounted to virus infection. The generation of NSs-lacking viruses was achieved by mapping the transcriptional termination of two S-segment-derived subgenomic mRNAs, which revealed that transcription termination occurs upstream of a 5'-GCCAGCC-3' motif present in the virus genomic S RNA.
Collapse
|
41
|
Differential Antagonism of Human Innate Immune Responses by Tick-Borne Phlebovirus Nonstructural Proteins. mSphere 2017; 2:mSphere00234-17. [PMID: 28680969 PMCID: PMC5489658 DOI: 10.1128/msphere.00234-17] [Citation(s) in RCA: 30] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2017] [Accepted: 06/05/2017] [Indexed: 12/24/2022] Open
Abstract
In recent years, several newly discovered tick-borne viruses causing a wide spectrum of diseases in humans have been ascribed to the Phlebovirus genus of the Bunyaviridae family. The nonstructural protein (NSs) of bunyaviruses is the main virulence factor and interferon (IFN) antagonist. We studied the molecular mechanisms of IFN antagonism employed by the NSs proteins of human apathogenic Uukuniemi virus (UUKV) and those of Heartland virus (HRTV) and severe fever with thrombocytopenia syndrome virus (SFTSV), both of which cause severe disease. Using reporter assays, we found that UUKV NSs weakly inhibited the activation of the beta interferon (IFN-β) promoter and response elements. UUKV NSs weakly antagonized human IFN-β promoter activation through a novel interaction with mitochondrial antiviral-signaling protein (MAVS), confirmed by coimmunoprecipitation and confocal microscopy studies. HRTV NSs efficiently antagonized both IFN-β promoter activation and type I IFN signaling pathways through interactions with TBK1, preventing its phosphorylation. HRTV NSs exhibited diffused cytoplasmic localization. This is in comparison to the inclusion bodies formed by SFTSV NSs. HRTV NSs also efficiently interacted with STAT2 and impaired IFN-β-induced phosphorylation but did not affect STAT1 or its translocation to the nucleus. Our results suggest that a weak interaction between STAT1 and HRTV or SFTSV NSs may explain their inability to block type II IFN signaling efficiently, thus enabling the activation of proinflammatory responses that lead to severe disease. Our findings offer insights into how pathogenicity may be linked to the capacity of NSs proteins to block the innate immune system and illustrate the plethora of viral immune evasion strategies utilized by emerging phleboviruses. IMPORTANCE Since 2011, there has been a large expansion in the number of emerging tick-borne viruses that have been assigned to the Phlebovirus genus. Heartland virus (HRTV) and SFTS virus (SFTSV) were found to cause severe disease in humans, unlike other documented tick-borne phleboviruses such as Uukuniemi virus (UUKV). Phleboviruses encode nonstructural proteins (NSs) that enable them to counteract the human innate antiviral defenses. We assessed how these proteins interacted with the innate immune system. We found that UUKV NSs engaged with innate immune factors only weakly, at one early step. However, the viruses that cause more severe disease efficiently disabled the antiviral response by targeting multiple components at several stages across the innate immune induction and signaling pathways. Our results suggest a correlation between the efficiency of the virus protein/host interaction and severity of disease.
Collapse
|
42
|
PJA2 ubiquitinates the HIV-1 Tat protein with atypical chain linkages to activate viral transcription. Sci Rep 2017; 7:45394. [PMID: 28345603 PMCID: PMC5366948 DOI: 10.1038/srep45394] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2016] [Accepted: 02/22/2017] [Indexed: 12/23/2022] Open
Abstract
Transcription complexes that assemble at the HIV-1 promoter efficiently initiate transcription but generate paused RNA polymerase II downstream from the start site. The virally encoded Tat protein hijacks positive transcription elongation factor b (P-TEFb) to phosphorylate and activate this paused polymerase. In addition, Tat undergoes a series of reversible post-translational modifications that regulate distinct steps of the transcription cycle. To identify additional functionally important Tat cofactors, we performed RNAi knockdowns of sixteen previously identified Tat interactors and found that a novel E3 ligase, PJA2, ubiquitinates Tat in a non-degradative manner and specifically regulates the step of HIV transcription elongation. Interestingly, several different lysine residues in Tat can function as ubiquitin acceptor sites, and variable combinations of these lysines support both full transcriptional activity and viral replication. Further, the polyubiquitin chain conjugated to Tat by PJA2 can itself be assembled through variable ubiquitin lysine linkages. Importantly, proper ubiquitin chain assembly by PJA2 requires that Tat first binds its P-TEFb cofactor. These results highlight that both the Tat substrate and ubiquitin modification have plastic site usage, and this plasticity is likely another way in which the virus exploits the host molecular machinery to expand its limited genetic repertoire.
Collapse
|
43
|
Terasaki K, Ramirez SI, Makino S. Mechanistic Insight into the Host Transcription Inhibition Function of Rift Valley Fever Virus NSs and Its Importance in Virulence. PLoS Negl Trop Dis 2016; 10:e0005047. [PMID: 27711108 PMCID: PMC5053439 DOI: 10.1371/journal.pntd.0005047] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2016] [Accepted: 09/17/2016] [Indexed: 11/18/2022] Open
Abstract
Rift Valley fever virus (RVFV), a member of the genus Phlebovirus within the family Bunyaviridae, causes periodic outbreaks in livestocks and humans in countries of the African continent and Middle East. RVFV NSs protein, a nonstructural protein, is a major virulence factor that exhibits several important biological properties. These include suppression of general transcription, inhibition of IFN-β promoter induction and degradation of double-stranded RNA-dependent protein kinase R. Although each of these biological functions of NSs are considered important for countering the antiviral response in the host, the individual contributions of these functions towards RVFV virulence remains unclear. To examine this, we generated two RVFV MP-12 strain-derived mutant viruses. Each carried mutations in NSs that specifically targeted its general transcription inhibition function without affecting its ability to degrade PKR and inhibit IFN-β promoter induction, through its interaction with Sin3-associated protein 30, a part of the repressor complex at the IFN-β promoter. Using these mutant viruses, we have dissected the transcription inhibition function of NSs and examined its importance in RVFV virulence. Both NSs mutant viruses exhibited a differentially impaired ability to inhibit host transcription when compared with MP-12. It has been reported that NSs suppresses general transcription by interfering with the formation of the transcription factor IIH complex, through the degradation of the p62 subunit and sequestration of the p44 subunit. Our study results lead us to suggest that the ability of NSs to induce p62 degradation is the major contributor to its general transcription inhibition property, whereas its interaction with p44 may not play a significant role in this function. Importantly, RVFV MP-12-NSs mutant viruses with an impaired general transcription inhibition function showed a reduced cytotoxicity in cell culture and attenuated virulence in young mice, compared with its parental virus MP-12, highlighting the contribution of NSs-mediated general transcription inhibition towards RVFV virulence. Rift Valley fever virus (RVFV) has a significant impact on the livestock industry because of its high mortality rate in young ruminants and causation of a high abortion rate in pregnant animals. Human RVFV infections generally manifest as self-limiting and non-fatal illnesses. However, a small percentage of patients develop encephalitis, vision loss and hemorrhagic fever with a high mortality rate. Currently, there is no commercially available vaccine for human use or effective antiviral drug for RVFV treatment. The non-structural protein NSs is a major virulence factor of RVFV, which mediates suppression of host general transcription, inhibition of IFN-β transcription and degradation of PKR, to block host antiviral responses. To examine the contribution of host transcription inhibition to RVFV virulence, we generated RVFV MP-12 strain-derived mutants that have attenuated inhibitory activity on host transcription due to amino acid mutations in NSs. The mutant viruses showed attenuated cytotoxicity in cell culture and attenuated virulence in young mice, demonstrating the contribution of NSs-mediated host transcription inhibition to the virulence of RVFV.
Collapse
Affiliation(s)
- Kaori Terasaki
- Department of Microbiology and Immunology, The University of Texas Medical Branch, Galveston, Texas, United States of America
| | - Sydney I. Ramirez
- Department of Pathology, The University of Texas Medical Branch, Galveston, Texas, United States of America
| | - Shinji Makino
- Department of Microbiology and Immunology, The University of Texas Medical Branch, Galveston, Texas, United States of America
- Center for Biodefense and Emerging Infectious Diseases, The University of Texas Medical Branch, Galveston, Texas, United States of America
- UTMB Center for Tropical Diseases, The University of Texas Medical Branch, Galveston, Texas, United States of America
- Sealy Center for Vaccine Development, The University of Texas Medical Branch, Galveston, Texas, United States of America
- The Institute for Human Infections and Immunity, The University of Texas Medical Branch, Galveston, Texas, United States of America
- * E-mail:
| |
Collapse
|
44
|
Pinkham C, An S, Lundberg L, Bansal N, Benedict A, Narayanan A, Kehn-Hall K. The role of signal transducer and activator of transcription 3 in Rift Valley fever virus infection. Virology 2016; 496:175-185. [PMID: 27318793 PMCID: PMC4969177 DOI: 10.1016/j.virol.2016.06.004] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2015] [Revised: 05/13/2016] [Accepted: 06/08/2016] [Indexed: 12/27/2022]
Abstract
Rift Valley fever (RVF) is a zoonotic disease that can cause severe illness in humans and livestock, triggering spontaneous abortion in almost 100% of pregnant ruminants. In this study, we demonstrate that signal transducer and activator of transcription 3 (STAT3) is phosphorylated on its conserved tyrosine residue (Y705) following RVFV infection. This phosphorylation was dependent on a major virulence factor, the viral nonstructural protein NSs. Loss of STAT3 had little effect on viral replication, but rather resulted in cells being more susceptible to RVFV-induced cell death. Phosphorylated STAT3 translocated to the nucleus, coinciding with inhibition of fos, jun, and nr4a2 gene expression, and the presence of STAT3 and NSs at the nr4a2 promoter. NSs was found predominantly in the cytoplasm of STAT3 null cells, indicating that STAT3 influences NSs nuclear localization. Collectively, these data demonstrate that STAT3 functions in a pro-survival capacity through modulation of NSs localization.
Collapse
Affiliation(s)
- Chelsea Pinkham
- National Center for Biodefense and Infectious Diseases, School of Systems Biology, George Mason University, 10650 Pyramid Place, Manassas, VA, United States
| | - Soyeon An
- National Center for Biodefense and Infectious Diseases, School of Systems Biology, George Mason University, 10650 Pyramid Place, Manassas, VA, United States
| | - Lindsay Lundberg
- National Center for Biodefense and Infectious Diseases, School of Systems Biology, George Mason University, 10650 Pyramid Place, Manassas, VA, United States
| | - Neha Bansal
- National Center for Biodefense and Infectious Diseases, School of Systems Biology, George Mason University, 10650 Pyramid Place, Manassas, VA, United States
| | - Ashwini Benedict
- National Center for Biodefense and Infectious Diseases, School of Systems Biology, George Mason University, 10650 Pyramid Place, Manassas, VA, United States
| | - Aarthi Narayanan
- National Center for Biodefense and Infectious Diseases, School of Systems Biology, George Mason University, 10650 Pyramid Place, Manassas, VA, United States
| | - Kylene Kehn-Hall
- National Center for Biodefense and Infectious Diseases, School of Systems Biology, George Mason University, 10650 Pyramid Place, Manassas, VA, United States.
| |
Collapse
|
45
|
Shao W, Zumer K, Fujinaga K, Peterlin BM. FBXO3 Protein Promotes Ubiquitylation and Transcriptional Activity of AIRE (Autoimmune Regulator). J Biol Chem 2016; 291:17953-63. [PMID: 27365398 PMCID: PMC5016183 DOI: 10.1074/jbc.m116.724401] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2016] [Revised: 06/20/2016] [Indexed: 12/16/2022] Open
Abstract
The autoimmune regulator (AIRE) is a transcription factor which is expressed in medullary thymic epithelial cells. It directs the expression of otherwise tissue-specific antigens, which leads to the elimination of autoreactive T cells during development. AIRE is modified post-translationally by phosphorylation and ubiquitylation. In this report we connected these modifications. AIRE, which is phosphorylated on two specific residues near its N terminus, then binds to the F-box protein 3 (FBXO3) E3 ubiquitin ligase. In turn, this SCF(FBXO3) (SKP1-CUL1-F box) complex ubiquitylates AIRE, increases its binding to the positive transcription elongation factor b (P-TEFb), and potentiates its transcriptional activity. Because P-TEFb is required for the transition from initiation to elongation of transcription, this interaction ensures proper expression of AIRE-responsive tissue-specific antigens in the thymus.
Collapse
Affiliation(s)
- Wei Shao
- From the Departments of Medicine, Microbiology, and Immunology, University of California, San Francisco, California 94143-07030703 and
| | - Kristina Zumer
- Max-Planck-Institute for Biophysical Chemistry, Department of Molecular Biology, Am Fassberg 11, 37077 Göttingen, Germany
| | - Koh Fujinaga
- From the Departments of Medicine, Microbiology, and Immunology, University of California, San Francisco, California 94143-07030703 and
| | - B Matija Peterlin
- From the Departments of Medicine, Microbiology, and Immunology, University of California, San Francisco, California 94143-07030703 and
| |
Collapse
|
46
|
Ly HJ, Ikegami T. Rift Valley fever virus NSs protein functions and the similarity to other bunyavirus NSs proteins. Virol J 2016; 13:118. [PMID: 27368371 PMCID: PMC4930582 DOI: 10.1186/s12985-016-0573-8] [Citation(s) in RCA: 65] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2016] [Accepted: 06/23/2016] [Indexed: 12/31/2022] Open
Abstract
Rift Valley fever is a mosquito-borne zoonotic disease that affects both ruminants and humans. The nonstructural (NS) protein, which is a major virulence factor for Rift Valley fever virus (RVFV), is encoded on the S-segment. Through the cullin 1-Skp1-Fbox E3 ligase complex, the NSs protein promotes the degradation of at least two host proteins, the TFIIH p62 and the PKR proteins. NSs protein bridges the Fbox protein with subsequent substrates, and facilitates the transfer of ubiquitin. The SAP30-YY1 complex also bridges the NSs protein with chromatin DNA, affecting cohesion and segregation of chromatin DNA as well as the activation of interferon-β promoter. The presence of NSs filaments in the nucleus induces DNA damage responses and causes cell-cycle arrest, p53 activation, and apoptosis. Despite the fact that NSs proteins have poor amino acid similarity among bunyaviruses, the strategy utilized to hijack host cells are similar. This review will provide and summarize an update of recent findings pertaining to the biological functions of the NSs protein of RVFV as well as the differences from those of other bunyaviruses.
Collapse
Affiliation(s)
- Hoai J Ly
- Department of Pathology, The University of Texas Medical Branch at Galveston, Galveston, TX, USA
| | - Tetsuro Ikegami
- Department of Pathology, The University of Texas Medical Branch at Galveston, Galveston, TX, USA. .,The Sealy Center for Vaccine Development, The University of Texas Medical Branch at Galveston, Galveston, TX, USA. .,The Center for Biodefense and Emerging Infectious Diseases, The University of Texas Medical Branch at Galveston, Galveston, TX, USA.
| |
Collapse
|
47
|
Wuerth JD, Weber F. Phleboviruses and the Type I Interferon Response. Viruses 2016; 8:v8060174. [PMID: 27338447 PMCID: PMC4926194 DOI: 10.3390/v8060174] [Citation(s) in RCA: 63] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2016] [Revised: 06/15/2016] [Accepted: 06/20/2016] [Indexed: 12/16/2022] Open
Abstract
The genus Phlebovirus of the family Bunyaviridae contains a number of emerging virus species which pose a threat to both human and animal health. Most prominent members include Rift Valley fever virus (RVFV), sandfly fever Naples virus (SFNV), sandfly fever Sicilian virus (SFSV), Toscana virus (TOSV), Punta Toro virus (PTV), and the two new members severe fever with thrombocytopenia syndrome virus (SFTSV) and Heartland virus (HRTV). The nonstructural protein NSs is well established as the main phleboviral virulence factor in the mammalian host. NSs acts as antagonist of the antiviral type I interferon (IFN) system. Recent progress in the elucidation of the molecular functions of a growing list of NSs proteins highlights the astonishing variety of strategies employed by phleboviruses to evade the IFN system.
Collapse
Affiliation(s)
- Jennifer Deborah Wuerth
- Institute for Virology, FB10-Veterinary Medicine, Justus-Liebig University, Giessen 35392, Germany.
| | - Friedemann Weber
- Institute for Virology, FB10-Veterinary Medicine, Justus-Liebig University, Giessen 35392, Germany.
| |
Collapse
|
48
|
NSs Virulence Factor of Rift Valley Fever Virus Engages the F-Box Proteins FBXW11 and β-TRCP1 To Degrade the Antiviral Protein Kinase PKR. J Virol 2016; 90:6140-7. [PMID: 27122577 PMCID: PMC4907219 DOI: 10.1128/jvi.00016-16] [Citation(s) in RCA: 42] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2016] [Accepted: 04/18/2016] [Indexed: 01/01/2023] Open
Abstract
Rift Valley fever virus (RVFV, family Bunyaviridae, genus Phlebovirus) is a relevant pathogen of both humans and livestock in Africa. The nonstructural protein NSs is a major virulence factor known to suppress the type I interferon (IFN) response by inhibiting host cell transcription and by proteasomal degradation of a major antiviral IFN effector, the translation-inhibiting protein kinase PKR. Here, we identified components of the modular SCF (Skp1, Cul1, F-box protein)-type E3 ubiquitin ligases as mediators of PKR destruction by NSs. Small interfering RNAs (siRNAs) against the conserved SCF subunit Skp1 protected PKR from NSs-mediated degradation. Consequently, RVFV replication was severely reduced in Skp1-depleted cells when PKR was present. SCF complexes have a variable F-box protein subunit that determines substrate specificity for ubiquitination. We performed an siRNA screen for all (about 70) human F-box proteins and found FBXW11 to be involved in PKR degradation. The partial stabilization of PKR by FBXW11 depletion upregulated PKR autophosphorylation and phosphorylation of the PKR substrate eIF2α and caused a shutoff of host cell protein synthesis in RVFV-infected cells. To maximally protect PKR from the action of NSs, knockdown of structurally and functionally related FBXW1 (also known as β-TRCP1), in addition to FBXW11 deletion, was necessary. Consequently, NSs was found to interact with both FBXW11 and β-TRCP1. Thus, NSs eliminates the antiviral kinase PKR by recruitment of SCF-type E3 ubiquitin ligases containing FBXW11 and β-TRCP1 as substrate recognition subunits. This antagonism of PKR by NSs is essential for efficient RVFV replication in mammalian cells. IMPORTANCE Rift Valley fever virus is a pathogen of humans and animals that has the potential to spread from Africa and the Arabian Peninsula to other regions. A major virulence mechanism is the proteasomal degradation of the antiviral kinase PKR by the viral protein NSs. Here, we demonstrate that NSs requires E3 ubiquitin ligase complexes of the SCF (Skp1, Cul1, F-box protein) type to destroy PKR. SCF-type complexes can engage variant ubiquitination substrate recognition subunits, and we found the F-box proteins FBXW11 and β-TRCP1 to be relevant for the action of NSs against PKR. Thus, we identified the host cell factors that are critically needed by Rift Valley fever virus to uphold its replication against the potent antiviral kinase PKR.
Collapse
|
49
|
Nishiyama S, Slack OAL, Lokugamage N, Hill TE, Juelich TL, Zhang L, Smith JK, Perez D, Gong B, Freiberg AN, Ikegami T. Attenuation of pathogenic Rift Valley fever virus strain through the chimeric S-segment encoding sandfly fever phlebovirus NSs or a dominant-negative PKR. Virulence 2016; 7:871-881. [PMID: 27248570 DOI: 10.1080/21505594.2016.1195528] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022] Open
Abstract
Rift Valley fever is a mosquito-borne zoonotic disease affecting ruminants and humans. Rift Valley fever virus (RVFV: family Bunyaviridae, genus Phlebovirus) causes abortions and fetal malformations in ruminants, and hemorrhagic fever, encephalitis, or retinitis in humans. The live-attenuated MP-12 vaccine is conditionally licensed for veterinary use in the US. However, this vaccine lacks a marker for the differentiation of vaccinated from infected animals (DIVA). NSs gene is dispensable for RVFV replication, and thus, rMP-12 strains lacking NSs gene is applicable to monitor vaccinated animals. However, the immunogenicity of MP-12 lacking NSs was not as high as parental MP-12. Thus, chimeric MP-12 strains encoding NSs from either Toscana virus (TOSV), sandfly fever Sicilian virus (SFSV) or Punta Toro virus Adames strain (PTA) were characterized previously. Although chimeric MP-12 strains are highly immunogenic, the attenuation through the S-segment remains unknown. Using pathogenic ZH501 strain, we aimed to demonstrate the attenuation of ZH501 strain through chimeric S-segment encoding either the NSs of TOSV, SFSV, PTA, or Punta Toro virus Balliet strain (PTB). In addition, we characterized rZH501 encoding a human dominant-negative PKR (PKRΔE7), which also enhances the immunogenicity of MP-12. Study done on mice revealed that attenuation of rZH501 occurred through the S-segment encoding either PKRΔE7 or SFSV NSs. However, rZH501 encoding either TOSV, PTA, or PTB NSs in the S-segment uniformly caused lethal encephalitis. Our results indicated that the S-segments encoding PKRΔE7 or SFSV NSs are attenuated and thus applicable toward next generation MP-12 vaccine candidates that encode a DIVA marker.
Collapse
Affiliation(s)
- Shoko Nishiyama
- a Department of Pathology , The University of Texas Medical Branch at Galveston , Galveston , TX , USA
| | - Olga A L Slack
- a Department of Pathology , The University of Texas Medical Branch at Galveston , Galveston , TX , USA
| | - Nandadeva Lokugamage
- a Department of Pathology , The University of Texas Medical Branch at Galveston , Galveston , TX , USA
| | - Terence E Hill
- a Department of Pathology , The University of Texas Medical Branch at Galveston , Galveston , TX , USA
| | - Terry L Juelich
- a Department of Pathology , The University of Texas Medical Branch at Galveston , Galveston , TX , USA.,b Galveston National Laboratory, The University of Texas Medical Branch at Galveston , Galveston , TX , USA
| | - Lihong Zhang
- a Department of Pathology , The University of Texas Medical Branch at Galveston , Galveston , TX , USA.,b Galveston National Laboratory, The University of Texas Medical Branch at Galveston , Galveston , TX , USA
| | - Jennifer K Smith
- a Department of Pathology , The University of Texas Medical Branch at Galveston , Galveston , TX , USA.,b Galveston National Laboratory, The University of Texas Medical Branch at Galveston , Galveston , TX , USA
| | - David Perez
- a Department of Pathology , The University of Texas Medical Branch at Galveston , Galveston , TX , USA
| | - Bin Gong
- a Department of Pathology , The University of Texas Medical Branch at Galveston , Galveston , TX , USA.,b Galveston National Laboratory, The University of Texas Medical Branch at Galveston , Galveston , TX , USA.,c The Center for Biodefense and Emerging Infectious Diseases, The University of Texas Medical Branch at Galveston , Galveston , TX , USA
| | - Alexander N Freiberg
- a Department of Pathology , The University of Texas Medical Branch at Galveston , Galveston , TX , USA.,b Galveston National Laboratory, The University of Texas Medical Branch at Galveston , Galveston , TX , USA.,c The Center for Biodefense and Emerging Infectious Diseases, The University of Texas Medical Branch at Galveston , Galveston , TX , USA.,d The Sealy Center for Vaccine Development, The University of Texas Medical Branch at Galveston , Galveston , TX , USA
| | - Tetsuro Ikegami
- a Department of Pathology , The University of Texas Medical Branch at Galveston , Galveston , TX , USA.,c The Center for Biodefense and Emerging Infectious Diseases, The University of Texas Medical Branch at Galveston , Galveston , TX , USA.,d The Sealy Center for Vaccine Development, The University of Texas Medical Branch at Galveston , Galveston , TX , USA
| |
Collapse
|
50
|
Making Bunyaviruses Talk: Interrogation Tactics to Identify Host Factors Required for Infection. Viruses 2016; 8:v8050130. [PMID: 27187446 PMCID: PMC4885085 DOI: 10.3390/v8050130] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2016] [Revised: 05/03/2016] [Accepted: 05/06/2016] [Indexed: 12/26/2022] Open
Abstract
The identification of host cellular genes that act as either proviral or antiviral factors has been aided by the development of an increasingly large number of high-throughput screening approaches. Here, we review recent advances in which these new technologies have been used to interrogate host genes for the ability to impact bunyavirus infection, both in terms of technical advances as well as a summary of biological insights gained from these studies.
Collapse
|